United States

Department of

Agriculture

Animal and Plant

Health Inspection

Service

Veterinary Services

Epidemiologic and Other Analyses of 

Indiana HPAI/LPAI-Affected Poultry Flocks:

March 18, 2016 Report
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

Suggested bibliographic citation for this report: 

USDA-APHIS (2016). Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks:

DRAFT March 4, 2016 Report. USDA:APHIS:VS:STAS:Center for Epidemiology and Animal Health. Fort 

Collins, CO. March 2016. 64 pgs.

For more information, contact: 

Bruce A. Wagner, PhD

Director, Center for Epidemiology and Animal Health

USDA:APHIS:VS:CEAH

2150 Centre Avenue, Bldg. B-2E7

Fort Collins, CO, 80526-8117

Phone (970) 494-7256

Mobile (970) 237-0857

Fax (970) 494-7228

Email: Bruce.A.Wagner@aphis.usda.gov

Web: http://www.aphis.usda.gov/animal-health/ceah

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Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only i

Contents

I. Executive Summary - Updated......................................................................................................1

II. Introduction - Updated ................................................................................................................2

III. Geospatial Assessment for H7N8 HPAI/LPAI Outbreak - Updated ..................................................3

A. Highlights of this Analysis........................................................................................................................ 3

B. Variables Considered for Geospatial Analysis......................................................................................... 3

C. Temperature and Precipitation............................................................................................................... 4

D. Federal Land and Watershed .................................................................................................................. 6

E. Other Attributes...................................................................................................................................... 7

F. Roads and Elevation................................................................................................................................ 9

G. Population at Risk..................................................................................................................................11

H. Conclusions ...........................................................................................................................................12

I. Next Steps.............................................................................................................................................12

J. References.............................................................................................................................................12

IV. Phylogenetic Analysis and Diagnostics - Updated........................................................................14

A. North American H7N8 Viruses..............................................................................................................14

B. Public Health Aspects............................................................................................................................16

C. Poultry Vaccine Strain Selection Considerations ..................................................................................16

D. Diagnostics and Characterization for Influenza A viruses.....................................................................16

V. Case-Control Study to Investigate H7N8 Virus in Turkeys in Indiana - Updated.............................17

A. Background ...........................................................................................................................................17

B. Description of Study..............................................................................................................................17

C. References.............................................................................................................................................20

VI. Preliminary Assessment of HPAI 2016 Mortality Sheet Data - NEW..............................................21

A. Findings.................................................................................................................................................21

B. Discussion..............................................................................................................................................22

C. Next steps..............................................................................................................................................22

VII. On-Farm Sampling: Preliminary Report - Updated.......................................................................23

A. Objective ...............................................................................................................................................23

B. Sampling Procedures.............................................................................................................................23

C. Laboratory Procedures..........................................................................................................................23

D. Results...................................................................................................................................................24

E. Summary ...............................................................................................................................................25

F. Acknowledgements...............................................................................................................................25

VIII. Literature Review ......................................................................................................................26

A. Latent and Infectious Periods for H7 HPAI Virus Strains.......................................................................26

Background................................................................................................................................................26

Bird-level infectious period and mean time to death for H7 HPAI ............................................................26

Bird-level latently infected period .............................................................................................................27

Summary and implications for current outbreak ......................................................................................27

B. Predominant Clinical Signs in Turkeys for Recent Outbreaks of H5 or H7 HPAI virus strains...............27

Background................................................................................................................................................27

Clinical signs in turkeys..............................................................................................................................28

C. References.............................................................................................................................................28
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Appendix A. Farm-Level Questions - Updated.....................................................................................30

Appendix B. Barn-Level Questions - Updated .....................................................................................37

Appendix C. HPAI Case Control Questionnaire....................................................................................41

Figure 1. Average daily maximum temperature by year for a 6-week period of December and early 

January. .................................................................................................................................................. 5

Figure 2. Average daily minimum temperature by year for a 6-week period of December and early 

January. .................................................................................................................................................. 5

Figure 3. Total precipitation by year for a 6- week period of December and early January. ....................... 5

Figure 4. Dubois County is downstream from and within the same watershed as Hoosier National 

Forest...................................................................................................................................................... 6

Figure 5. Percentage of county comprised of cropland. 2014 NASS Cropscape. ......................................... 7

Figure 6. Percentage of county comprised of open water (2014 NASS Cropscape)..................................... 8

Figure 7. Percentage of county that is comprised of wetland (2014 NASS Cropscape). .............................. 8

Figure 8. The connecting route consists of four different roads. ................................................................. 9

Figure 9. NASS 2012 turkey and chicken inventory of poultry by county. ................................................. 11

Figure 10. Schematic phylogenetic tree of the HA1 nucleotide sequences of H7 AIVs.............................. 14

Figure 11. Median farm mortality rates by week ....................................................................................... 21

Table 1. Variables evaluated geospatially..................................................................................................... 3

Table 2. 2 x 2 table denoting the connectivity of the connecting route to the infected and 

uninfected premises............................................................................................................................. 10

Table 3. 2 x 2 table denoting the effect of distance to infected and uninfected premises........................ 10

Table 4. 2 x 2 table denoting the effect of hilltop to infected and uninfected premises........................... 11

Table 5. Major differences between 2014-15 Eurasian H5 viruses and the North American H7N8 

influenza A viruses (IAV)....................................................................................................................... 15

Table 6. Farm-level characteristics ............................................................................................................. 18

Table 7. Barn-level characteristics.............................................................................................................. 19

Table 8. Summary of Infected Flocks.......................................................................................................... 23

Table 9. Summary of Samples Collected..................................................................................................... 24

Table 10. Summary of Animals Sampled .................................................................................................... 24

Table 11. Summary of positive samples for avian serum samples tested by ELISA ................................... 24

Table 12. Summary of infectious period and time to death data for H7 HPAI strains ............................... 26

Table 13. Summary of bird-level latent period data for H7 HPAI strains ................................................... 27

Table 14. Summary of primary clinical signs seen in turkeys during recent outbreaks by HPAI strain...... 28
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 1

I. EXECUTIVE SUMMARY - UPDATED

In mid-January, a combined outbreak of highly pathogenic avian influenza and low pathogenic avian 

influenza (HPAI and LPAI) occurred in Indiana. The outbreak in commercial turkeys was first 

detected by an increase in mortality followed by laboratory confirmation of H7N8 HPAI. After initial 

efforts to control the disease, a series of epidemiologic, geospatial, genetic, and wildlife 

investigations was started. These studies are being conducted collaboratively with the poultry 

industry, the Indiana State Board of Animal Health, and the United States Department of 

Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS). This is the second report of 

the findings available to date to assist in understanding the introduction and disease transmission 

pathways. Ultimately, the goal is to reduce the risk of continued spread in this outbreak and to help 

in future efforts to prevent disease incursions. This report is the final epidemiologic report for this 

incident, although additional analyses may be undertaken and reported through other mechanisms.

Genetic analyses determined that all H7N8 viruses detected from this event are of North American 

wild bird lineage, and the HPAI and LPAI viruses are highly similar across all eight genes excluding 

the multi-basic amino acid insertion at the cleavage site in the HPAI virus. Genetic analysis also 

suggests a point source introduction followed by lateral/secondary spread.

An investigation of cases and controls using an in-person administered questionnaire examined 

physical and management characteristics of infected premises. Differences were identified between 

case farms and barns compared to control farms and barns. Several risk factors found in a previous

HPAI case-control study were found to occur on more case farms and in case barns than on control 

farms and in control barns. These factors included distance to dead bird disposal and litter compost 

areas, presence of wild mammals, and visitors entering barns. 

Additionally, daily mortality sheets were obtained from both case and control farms. Mortality 

patterns from these farms between September 7, 2015, and January 17, 2016, were compared. This 

comparison showed differences in mortality between case and control farms for 2 weeks in October 

2015 and again in November 2015. However, there were no major differences in mortality patterns 

between case and control farms in closer temporal proximity to the identified H7N8 HPAI outbreak.

APHIS has completed sampling and testing of wildlife near infected premises. The results indicate no 

evidence of existing virus in the samples from wild birds and mammals tested.

Initial geospatial analysis looked at county-level factors that may have contributed to the 

introduction of the virus into Dubois County, Indiana. The weather in Dubois County was warmer 

and wetter than past years, which may have contributed to the introduction and persistence of the 

virus. Additional analysis identified a geospatial pattern observed between infected premises and a 

driving route. More detailed geospatial analysis is ongoing. 
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II. INTRODUCTION - UPDATED

In 2015, the United States experienced an outbreak of highly pathogenic avian influenza (HPAI) that 

was the largest animal health emergency in history. Many lessons were learned from that 

experience, including the need to understand the outbreak to help prevent and control future 

outbreaks. Since the end of the outbreak in the summer of 2015, the United States Department of 

Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS), States, and the poultry 

industry have been preparing on many fronts for potential outbreaks in the fall of 2015 or in 2016. 

The January 2016 combined outbreak of HPAI and low pathogenic avian influenza (LPAI) in Indiana 

has challenged the preparations all the groups have made. In response to the outbreak, APHIS 

Veterinary Services (VS) – in collaboration with the Indiana State Board of Animal Health and the 

southern Indiana poultry industry – has undertaken a number of epidemiologic, geospatial, and 

laboratory-based investigations. 

These investigations include:

• A field-based study of cases and controls using data collected through personal interviews 

with farm personnel; 

• geospatial analyses; 

• on-farm sampling of wildlife;

• phylogenetic investigations; and

• an assessment of mortality data

This report updates the previous summary of preliminary findings from these studies. Although this 

report is intended to be the last epidemiologic report for this outbreak, additional analyses will be 

completed to provide information to producers, industry, and other stakeholders on how the 

disease may have been introduced and spread to help with current and future mitigation efforts. 
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III. GEOSPATIAL ASSESSMENT FOR H7N8 HPAI/LPAI OUTBREAK - UPDATED

APHIS completed a county-level analysis on available data for Dubois County, Indiana, and 

surrounding counties. The focus was on descriptive epidemiology that could explain why Dubois 

County experienced an HPAI and LPAI outbreak of H7N8 in early 2016 based on available geospatial 

data. The analysis focused on the introduction of H7N8 LPAI by wild waterfowl and environmental 

conditions that may have or have not supported this introduction. 

A. Highlights of this Analysis

• The mean high and mean low temperatures for the 6 weeks leading up to the outbreak 

were warmer than the previous 2 years and were conducive to Influenza A virus survival. 

• Precipitation in 2016 in the 6 weeks leading up to the outbreak was higher than in 2015, but 

lower than 2014. However, when paired with generally warmer temperatures, the 

environment was still likely conducive to support survival of H7N8. 

• Dubois County is in the same watershed as and downstream from a large reservoir and the 

Hoosier National Forest, possible sources of LPAI virus introduction into the area. 

• Presence of cropland in Dubois County did not appear to be a factor that influenced the 

presence of H7N8 LPAI-infected waterfowl relative to other counties. 

• Dubois County was at the lower range for sources of open water in relation to other 

counties. Therefore, open water is not considered a factor that may have increased the 

presence of infected waterfowl in Dubois County compared to other counties. 

• Dubois County has one of the higher densities of poultry compared to surrounding counties 

and therefore had a larger susceptible population for introduction of LPAI into commercial 

poultry. 

• There was a strong pattern observed between infected premises and a common driving 

route, which followed a general north-to-south direction. 

B. Variables Considered for Geospatial Analysis

Multiple variables were assessed geospatially to help explain why the avian influenza virus may have 

been present in the Dubois County area in the late fall/early winter of 2015-2016. Table 1 below 

outlines the variables and their respective findings. 

Table 1. Variables evaluated geospatially

Measured Variable Observation Notes

Outdoor Temperature Mean high and low temps higher Evaluated 6 weeks prior to first 

detection; Compared to past 2 years

Precipitation Total precipitation higher in six 

weeks prior to outbreak than 

previous year, yet lower than in 

2014.

Evaluated 6 weeks prior to first 

detection; Compared to past 2 years

Watershed connectivity Watershed connectivity to Hoosier 

National Forest and nearby large 

reservoir 

May have allowed for introduction 

of LPAI into the area via connected 

watersheds
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

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Measured Variable Observation Notes

Presence of cropland Presence or absence of cropland in 

the area was not a factor

Data for specific crop type(s) 

near/around the infected premises 

was not available and therefore not 

evaluated

Open water source Open water source was not a factor ...

Poultry density Higher poultry population provided 

a susceptible population

Dubois County did have a denser 

poultry population than surrounding 

counties

Elevation of operation Had some association with disease Limited number of infected premises 

could not lend statistical significance 

and was confounded with the 

location of the road

Roads – distance and direction Had likely association with disease 

outbreak

Strong pattern observed between 

infected premises and common 

driving route

Barn directional orientation Orientation (N,S,E,W) was not a 

factor

No observable pattern among or 

between infected and uninfected 

barns in the control zone

North-to-south orientation of 

infected premises

No discernable explanation at this 

time

A greater number of infected 

premises may have lent more ability 

to statistically evaluate variables 

related to this

C. Temperature and Precipitation

Temperature and moisture are factors that influence migration patterns in some waterfowl (Austin 

et al., 2002). Temperature and moisture for a 6-week period prior to detection in January 2016 were 

compared to the same period in the previous 2 years. The mean high temperature in 2016 was 

higher than 2 previous years (Figure 1). The mean high was 50.88 degrees Fahrenheit and the mean 

low was 34.04 degrees Fahrenheit—above freezing temperatures (Figure 2). These temperatures 

have been shown to be conducive to persistence of avian influenza virus in the environment. 

Precipitation in the 2016 period was higher than 2015, but lower than 2014 (Figure 3). However, 

when paired with temperature information, the moisture in 2016 may have created an environment 

conducive to H7N8 LPAI survival and the presence of waterfowl. 
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

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Figure 1. Average daily maximum temperature by year for a 6-week period of December and early January.

Figure 2. Average daily minimum temperature by year for a 6-week period of December and early January.

Figure 3. Total precipitation by year for a 6- week period of December and early January.
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

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D. Federal Land and Watershed

Avian influenza viruses have been isolated from water where waterfowl congregate, even after the 

birds have moved (Ito et al., 1995). Hoosier National Forest is the largest contiguous land area in 

Indiana that is unaltered by agriculture or urban development (Leatherberry, 2002). Habitats such as 

Hoosier National Forest create important areas for resting, feeding, or other uses for migratory 

waterfowl (Kaminski et al., 1989; Leatherberry, 2002). The watersheds that included all 10 infected

premises also were hydrologically connected with Hoosier National Forest (Figure 4). Favorable 

conditions (see Temperature and Precipitation section) within a watershed may attract waterfowl 

during winter months (Kaminski et al., 1989). If waterfowl were to follow the watershed, or if heavy 

rains washed feces from infected waterfowl in Hoosier National Forest downstream to Dubois 

County, these conditions could create an opportunity for introduction into Dubois County that was 

not shared with other counties in Indiana. 

Figure 4. Dubois County is downstream from and within the same watershed as 

Hoosier National Forest.
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USDA APHIS VS – For Internal Use Only 7

E. Other Attributes 

An assessment of H5N2 HPAI in Minnesota indicated the presence of cropland may contribute to the 

presence of infected waterfowl. Cropland is an important component of migratory waterfowl 

habitat (Kaminski et al., 1989). In Indiana, the percentage of cropland in the counties studied ranged 

between 3.5 and 78 percent. Cropland did not appear to be a factor that influenced the presence of 

H7N8 LPAI-infected waterfowl in Dubois County relative to other counties (Figure 5). Additional 

analysis of water usage within crops, the type of crops, and proximity to infected premises may 

provide additional information. 

The percentage of wetland and open water was also explored as possibly important for waterfowl 

migration (Bellrose and Trudeau, 1987). Dubois County was again in the lower range of the 

spectrum and these attributes were not considered factors that influence the presence of infected 

waterfowl in Dubois County relative to neighboring counties (Figure 6 and Figure 7). 

Figure 5. Percentage of county comprised of cropland. 2014 NASS 

Cropscape.
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

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\

Figure 7. Percentage of county that 

is comprised of wetland (2014 

NASS Cropscape).

Figure 6. Percentage of county 

comprised of open water (2014 

NASS Cropscape).
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

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F. Roads and Elevation

Two geospatial assessments were conducted to address the apparent association of roads to 

reported cases. The first assessment, also known as a connectivity test, evaluated the direct 

connection between cases and a common network of north-to-south roadways, heretofore referred 

to as the connecting route. The connecting route consists of four different roads: Highway 545, East 

Jasper Dubois Road, North Steinbottom Road, and Highway 164 (Figure 8).

Figure 8. The connecting route consists of four different roads.
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The second assessment compared distance of cases to the connecting route. A distance of 500 

meters was selected to compare results with previous AI outbreak studies (personal communication, 

Malladi, S., Weaver, J.T.). Comparisons were made between those premises that were within 500 

meters from the connecting route and those premises that were at a distance greater than 500 

meters. Specific routes of traffic, such as routes of feed trucks or other company trucks, were not 

available and therefore not included in this analysis.

The connectivity test indicated that eight of 15 premises that directly linked to the connecting route 

were infected, compared to one of 50 of not connected premises that was infected (Table 2). The 

relative risk was 26.67 (3.62, 196.49). 

Table 2. 2 x 2 table denoting the connectivity of the connecting route to the infected and uninfected 

premises

HP/LPAI No Detection Total

Connected 8 7 15

Not connected 1 49 50

Total 9 56 65

Estimate Lower 95% CI Upper 95% CI

Prevalence Odds Ratio 56.00 6.05 518.01

Relative Risk 26.67 3.62 196.49

The assessment of distance to the connecting route indicated that six of the eight premises that 

were within 500 meters from the common connecting route were infected when compared to three 

of 57 premises infected that were outside 500 meters (Table 3). The relative risk was 14.25 (4.41, 

46.00).

Table 3. 2 x 2 table denoting the effect of distance to infected and uninfected premises

HP/LPAI No Detection Total

Within 500m 6 2 8

Outside 500m 3 54 57

Total 9 56 65

Estimate Lower 95% CI Upper 95% CI

Prevalence Odds Ratio 54.00 7.47 390.35

Relative Risk 14.25 4.41 46.00

These observations suggest that the common connecting route might be a key component in the 

observed north-south pattern of infected premises reported in this outbreak. The network of northto-south roadways may have served as a point source for spreading the virus through movement of 

birds, personnel, feed, litter, or compost. These resources have been implicated in spread of LPAI in 

past outbreaks (Vieira et al., 2009; Halvorson, 2009).

One of the companies evaluated their movement records along this connecting route for the 30 

days prior to HPAI detection and provided the following information. They evaluated supervisor 

movement and live bird-haul truck movement (both full and empty trucks). The only identified 

vehicles from those evaluated movements that travelled the entire connecting route were empty 

live-haul trucks. These trucks were disinfected with hot water wash prior to leaving the processing 

premises. Data for the movement of litter trucks and feed trucks was not available for evaluation, 

but the company noted that no common feed truck would have visited all the infected premises.
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

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Field observations indicated premises on hilltops were more commonly infected compared to 

premises in a valley. Six of the 25 premises that were on hilltops were infected when compared to 

three of 40 premises that were in valleys that were infected (Table 4). The relative risk was 3.2 (0.87, 

11.66). While this is indicative of an association, it does not account for location of the road, which 

also follows the slope and is a likely confounder in this analysis. 

Table 4. 2 x 2 table denoting the effect of hilltop to infected and uninfected premises

HP/LPAI No Detection Total

On hilltop 6 19 25

Not on hilltop 3 37 40

Total 9 56 65

Estimate Lower 95% CI Upper 95% CI

Prevalence Odds 

Ratio

3.89 0.88 17.32

Relative Risk 3.20 0.88 11.66

G. Population at Risk

For HPAI/LPAI to enter a poultry population, the virus must enter the environment and have a 

susceptible population to infect. Dubois County has one of the higher densities of poultry compared 

to its neighboring counties (Figure 9). 

Figure 9. NASS 2012 turkey and chicken inventory of poultry 

by county.
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

12 USDA APHIS VS – For Internal Use Only 

H. Conclusions

This assessment describes the large-scale attributes present that may have influenced the 

introduction of the H7N8 virus and identifies a few hypotheses about these attributes, which could 

stimulate future studies. However, it is not possible to determine if wild birds persisted in this area 

due to environmental conditions, or if waterfowl behavior in late 2015 and early 2016 was normal 

but management practices influenced the introduction, or whether other factors led to the 

introduction of H7N8.

Several environmental factors present in Dubois County appeared to differ from neighboring 

counties (watershed connectivity, presence of a dense poultry population) or from previous years

(higher temperature and precipitation); however, a statistical analysis was not completed at this 

time. While temperature and precipitation in the counties examined did not appear different from 

Dubois, those conditions may have been favorable for migratory waterfowl to remain longer in 

Indiana. The presence of a large mass of public land with accessible water may also have attracted 

waterfowl, although this area of Indiana may be where waterfowl normally congregate during 

migration. 

If infected waterfowl were present, Dubois County is downstream and within the same watershed of

Hoosier National Forest; therefore, birds or their feces may have moved into the county. 

Neighboring counties downstream did not have as sizeable of a poultry population to become 

infected. 

Results from the road assessment indicate that a premises’ proximity to the identified common 

route may have been a risk factor for developing infection, yet no specific vehicle movement or 

other variable can be attributed to that risk at this time.

I. Next Steps

Additional analysis of environmental conditions in previous LPAI outbreaks would help determine if 

the environmental conditions present in Dubois County were a contributing factor(s) to the 

presence of infected waterfowl and subsequent poultry infection. Given the likely association 

between the north-south connecting route, it may be valuable to investigate more specific vehicle 

movement along this common route to analyze whether an association can be made among 

resource movement patterns and infected premises. 

J. References

Austin, J.E., Granfors, D.A., Johnson, M.A., Kohn, S.C., 2002. Scaup migration patterns in North Dakota relative 

to temperatures and water conditions. The Journal of wildlife management, 874-882.

Bellrose, F.C., Trudeau, N.M., 1987. Wetlands and Their Relationship to Migrating and Winter Populations of 

Waterfowl. The Ecology and Management of Wetlands: Volume 1: Ecology of Wetlands. Springer US, 

Boston, MA, 183-194.

Halvorson, D.A., 2009. Prevention and management of avian influenza outbreaks: experiences from the United 

States of America. Revue scientifique et technique (International Office of Epizootics) 28(1), 359-69.

Ito, T., Okazaki, K., Kawaoka, Y., Takada, A., Webster, R.G., Kida, H., 1995. Perpetuation of influenza A viruses 

in Alaskan waterfowl reservoirs. Archives of Virology 140, 1163-1172.

Kaminski, R.M., Moorhead, D.J., Hodges, J., Nassar, J., 1989. Mississippi alluvial valley. Habitat management 

for migrating and wintering waterfowl in North America. Texas Tech Univ. Press, Lubbock, 203-247.
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 13

Leatherberry, E.C., 2002. The forest resources of the Hoosier National Forest, 1998. US Department of 

Agriculture, Forest Service, North Central Research Station.

Malladi, S., Weaver, J.T., 2013. Exposure Assessment: Estimates the likelihood of susceptible poultry becoming 

exposed to HPAI released due to movement of broilers.

Vieira, A.R., Hofacre, C.L., Smith, J.A., Cole, D., 2009. Human contacts and potential pathways of disease 

introduction on Georgia poultry farms. Avian Diseases 53(1), 55-62.
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

14 USDA APHIS VS – For Internal Use Only 

IV. PHYLOGENETIC ANALYSIS AND DIAGNOSTICS - UPDATED

A. North American H7N8 Viruses

This report describes the H7N8 HPAI virus from a commercial turkey flock in Dubois County, Indiana, 

confirmed by the National Veterinary Services Laboratories (NVSL) in January 2016.1 The NVSL 

confirmed H7N8 HPAI in the index flock by cleavage site analysis from partial hemagglutinin (HA) 

gene sequence obtained directly from the sample. Eight subsequent H7N8 detections from control 

zone surveillance were confirmed to be LPAI with high similarity to the HPAI virus excluding the 

insertion at the cleavage site in the HPAI virus. Due to the potential risk of mutation, control actions 

appropriate to HPAI were followed. There have been no further detections since January 16. 

This is the first detection of an H7N8 HPAI virus. The H7N8 viruses are not related to the Eurasian H5 

HPAI viruses from 2014-15. Based upon the full genome sequence2 of eight H7N8 viruses 

representing seven different premises, the index case of H7N8 HPAI and subsequent detection of 

H7N8 LPAI are of North American wild bird lineage with high similarity to other recent wild bird 

viruses (North American Cluster III viruses; blue box in Figure 103

). They are highly similar to each 

other across all eight genes (excluding the multi-basic amino acid insertion at the cleavage site 

responsible for the mutation to HPAI). The H7N8 HPAI and LPAI viruses are also highly similar across 

six of eight gene segments to a recent wild bird detection of H7N8 LPAI in Kentucky (lesser scaup 

collected November 28, 2015). This suggests that reassortment, which is common to influenza A 

viruses in wild birds, occurred prior to the virus being introduced in turkeys in Indiana. However, the 

mutation to the highly pathogenic form identified at a single farm likely occurred during replication 

of the virus in poultry.

 1 Virus availability announcement: 

https://www.aphis.usda.gov/animal_health/vet_biologics/publications/notice_16_02.pdf

2 Genbank IDs: H7N8 HPAI KU558903-8910; H7N8 LPAI KU585905-12 and KU585913-20

3 Xu Y, Bailey E, Spackman E, et al. 2016. Contemporary H7 Avian-Origin Influenza A Viruses from North America (Scientific 

Reports, 6: 20688) 

The tree was constructed based on the phylogeny 

inferred by using the maximum-likelihood method. 

Boxes represent the 3 major genetic clusters; the

Eurasian lineage (EU) is represented by the large 

black triangle. Am = North American lineage. 

The H7N8 viruses are located in Cluster III. 

Courtesy of Xi-Feng Wan et al, Department of 

Basic Sciences, College of Veterinary Medicine, 

Mississippi State University.

Figure 10. Schematic phylogenetic tree of the 

HA1 nucleotide sequences of H7 AIVs.
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 15

Additional genetic analysis of the eight H7N8 viruses for which whole genome sequence was 

obtained suggests a point source introduction followed by lateral/secondary spread, and provides 

potential insight into virus evolution and the epidemiology of this outbreak. 

In general, influenza A viruses, including H5 and H7 subtypes, circulate in wild waterfowl in a form

that is low pathogenic for chickens, and to date H7 HPAI viruses have been documented after the 

virus has circulated in poultry. The only H5s recognized to circulate in wild birds in a form that is 

highly pathogenic for chickens are the goose Guangdong-lineage viruses, such as those involved in 

the Eurasian H5 clade 2.3.4.4 outbreak in 2014-15 (Table 5). North American H7N8 LPAI virus has 

been previously detected in wild bird surveillance in the United States, but this is the first instance 

of H7N8 HPAI virus detection in any species. 

All H7N8 viruses detected from this event are of North American wild bird lineage, the 

HPAI and LPAI viruses are highly similar across all eight genes, excluding the multibasic 

amino acid insertion at the cleavage site in the HPAI virus, and genetic analysis suggests a 

point source introduction followed by lateral/secondary spread.

Table 5. Major differences between 2014-15 Eurasian H5 viruses and the North American H7N8 influenza A 

viruses (IAV).

Eurasian (EA) H5N8 EA/AM H5N2 reassortant North American (AM) H7N8

Related to Asian H5N8? Yes

(all 8 genes)

Yes 

(5 genes)

No 

(not even N8)

Related to North 

American IAV? No Yes (3 genes)

Yes

(all 8 genes)

Was the initial virus 

adapted to poultry? No No Unlikely - research in progress

Were virus adaptations 

noted after circulation in 

poultry?

Yes (CA) Yes (Midwest) Yes (LPAI>HPAI)

Species adaptation/ virus 

infectivity

The initial viruses detected in the U.S. were poorly 

adapted to poultry with low infectivity and had 

prolonged mean death times; unlike previous Asian 

H5N1 viruses, the Eurasian H5 viruses may initially 

circulate undetected

Research in progress – the 

H7N8 is a wild bird lineage 

virus, and like other LPAI 

viruses may circulate 

undetected 

Reservoir

The Asian H5 lineage (goose Guangdong 1996) are the 

only HPAI viruses recognized to circulate in wild 

waterfowl and may be the result of spillover from 

domestic poultry into wild birds in Asia - Prior to 1996, 

no HPAI viruses were recognized to circulate in wild 

birds

Wild waterfowl are the 

natural reservoir for influenza 

A viruses (H1-H16)

Mode of spread

Molecular/epi data supports point source introduction 

and lateral/secondary spread occurring at the same 

time (esp. early in Midwest turkeys); outbreaks at the 

end of the epi curve largely attributed to 

lateral/secondary spread 

Molecular data supports 

point source introduction 

with subsequent 

lateral/secondary spread

Control No difference - stamp out HPAI
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

16 USDA APHIS VS – For Internal Use Only 

B. Public Health Aspects

No cases of H7N8 HPAI virus infection have been reported in humans at this time, and no human 

infections associated with avian influenza A viruses of this particular subtype (i.e., H7N8) have ever 

been reported.

All viruses to date lack key amino acid substitutions associated with human-like receptor binding or 

substitutions in the polymerase or other internal genes associated with increased virulence and 

transmission in mammals.

No known markers of neuraminidase inhibitor (Oseltamivir) resistance have been identified.

Efforts to monitor the health of response workers and on-farm personnel continue. 

C. Poultry Vaccine Strain Selection Considerations

Genetic, antigenic, and growth characteristics are considered for selection of poultry candidate 

strains. Experimental studies in poultry indicate that antibody to the neuraminidase protein does 

not play a significant role in protection. Antigenic characteristics and challenge studies will be used 

to evaluate protection of existing and candidate vaccines; ongoing evaluation of viruses for antigenic 

drift will continue.

D. Diagnostics and Characterization for Influenza A viruses

Molecular diagnostic tests for influenza A virus (IAV) are used across the National Animal Health 

Laboratory Network (NAHLN) in the United States. As primary surveillance tools, the NAHLN H5 and 

H7 assays are broadly reactive, and do not distinguish geographic lineage or pathotype. There were 

no issues with detection of the H7N8 viruses from Indiana using the NAHLN assays. The NVSL uses 

Sanger sequencing protocols to generate partial HA/NA sequence directly from the sample for 

confirmation, pathotyping, and subtype determination where sufficient virus is present. Whole 

genome sequencing is conducted on all isolated viruses and select viruses are further characterized 

by pathotype assay in specific pathogen-free chickens. 

USDA’s NVSL collaborates with the Southeast Poultry Research Laboratory (SEPRL), the Influenza 

Division of the Centers for Disease Control and Prevention (CDC), and other key partners to rapidly 

share genetic and biological materials. Consensus data from whole genome sequencing is used to 

monitor the virus evolution and assess risk to veterinary or public health based upon 

presence/absence of specific amino acid substitutions or protein motifs. Analysis of sequence data 

includes phylogeny of all eight segments and determination of amino acid substitutions across the 

HA1 protein.
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 17

V. CASE-CONTROL STUDY TO INVESTIGATE H7N8 VIRUS IN TURKEYS IN INDIANA -

UPDATED

A. Background

USDA-APHIS conducted a case-control study among commercial turkey operations in Indiana to 

investigate potential risk factors for infection with H7N8 avian influenza virus. We conducted inperson interviews with producers on nine case farms where H7N8 was detected (HPAI, n=1; LPAI,

n=8) and 30 control farms located within the control area. Respondents were instructed to answer 

questions for the 2-week time period from Jan. 1 to Jan. 14, 2016. The questionnaire addressed 

general premises characteristics, biosecurity practices, wild birds, employees and visitors, vehicles 

and equipment, litter handling, and dead bird disposal (see appendix). In addition, questions were 

asked about one infected barn (case farms) or one barn containing birds during the 2-week time 

period (control farms). Data were entered into a SAS data set. Statistical comparisons between case 

and control farms, including potential confounding influence of one variable upon another, were not 

attempted because the number of case farms was small. The percentage of case farms and control 

farms having farm-level (Table 6) and barn-level (Table 7) characteristics for selected variables are 

reported here. Results for the complete set of variables are included in the appendix.

B. Description of Study

Although case and control farms were similar in size (total number of birds), control farms had more 

employees than case farms and control barns held more birds than case barns. Birds on case farms 

were older than birds on control farms. The percentage of control barns with young birds may have 

been somewhat biased due to selling off birds close to market age. However, none of the case barns 

had birds younger than 8 weeks of age (as of Jan. 14, 2016) compared to nearly half of control barns. 

Additionally, one-third of case farms versus two-thirds of control farms reported that they raised 

brooder birds on the farm. Temperatures in control barns were higher than in case barns, which 

may be related to having younger birds.

Over half of case farms and about one-fourth of control farms were located east of a public road. 

Case barns and control barns were located a similar distance from the nearest road, but case barns 

were located closer than control barns to dead bird disposal and litter compost areas. Being near a 

dead bird disposal area was found to be a risk factor in a previous HPAI case-control study on table 

egg layer farms (USDA 2015). All case farms and three-fourths of control farms had any water bodies 

located within 350 yards of the farm. Ponds were located within 350 yards of all case farms and 60 

percent of control farms. Waterfowl and other birds were rarely observed on the farm, in nearby 

fields, or on water bodies during the 14 days prior to detection of infection on either case or control 

farms (see appendix). Wild mammals were seen more frequently on case farms. Also, poultry feed 

was accessible to wild birds, wild animals, and rodents on a higher percentage of case farms than 

control farms. Presence of wild mammals was found to be a risk factor in a previous LPAI (H7) casecontrol study in Virginia (McQuiston et al., 2005).

A higher percentage of case farms than control farms had any visitors enter a barn; in particular, 

veterinarians, company service persons, and occasional workers. A higher percentage of case barns 

than control barns were dealing with another health concern in the flock, so it is possible the 

veterinarian or service person visit may have been related to this problem. Company service person 

visit was found to be a risk factor in the previous HPAI case-control study on table egg layer farms. 
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

18 USDA APHIS VS – For Internal Use Only 

One-third of case farms had a hard surface entry pad that was cleaned and disinfected, compared to 

two-thirds of control farms. This practice was found to be a protective factor in the previous HPAI 

case-control study on table egg layer farms.

Table 6. Farm-level characteristics

Characteristic Percent case farms Percent control farms

Farm size (number of birds on farm on reference date):

Less than 20,000 44 55

20,000 or more 56 45

Stage of production:

Brooder 33 62

Grower 100 93

Breeders 0 0

Other 0 0

If both grower and brooder:

In different barns 100 100

Sex of market type:

Hens (HH or LH) 0 10

Toms (FP) 100 87

Both hens and toms 0 3

Any water bodies within 350 yards: 100 77

Pond 100 60

Direction from public road to farm:

East/NE/SE 56 27

Wild mammals (or evidence) observed in or around 

poultry barns during the 14-day defined risk period 88 41

Access to poultry feed:

Wild birds 38 10

Wild animals 38 10

Rodents 25 3

Number of employees:

1 38 7

2 25 29

3 or more 38 64

Visitor type during the 14-day risk period: Visitors1

Avg # 

times2

Entered 

barn3 Visitors1

Avg # 

times2

Entered 

barn3

Private or company veterinarian 13 2 25 0

Company service person 88 2 88 72 2 57

Catch crew (bird removal) 25 1 14 7 1 10

Feed delivery personnel 88 8 13 97 4 8

Occasional worker (e.g., family member, part-time 

help over holiday) 50 8 38 23 2 20

Any visitors enter the barn 100 57

1Percent of all farms that had the visitor

2For farms with the visitor 3Percent of farms where the visitor entered the barn, out of all farms (with and without the visitor)
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 19

Table 7. Barn-level characteristics

Characteristic Percent case barns Percent control barns

Number of birds placed in this barn:

Fewer than 4,000 0 4

4,000 to 9,999 100 64

10,000 or more 0 32

Type(s) of poultry are present in this barn:

Brooder 0 26

Grower toms 100 74

Grower hens 0 4

Breeders 0 0

Other 0 0

Age of birds (weeks):

Less than 8 0 44

8 to less than 14 25 15

14 or more 75 41

Another health concern in this flock during the defined risk 

period 44 11

Hard-surface entry pad (e.g., concrete, asphalt):

Cleaned and disinfected 33 68

Cleaned only 11 14

Not cleaned or disinfected 33 7

No hard-surface entry pad 22 11

Types of people who entered this barn during the 14-day 

defined risk period:

Private or company veterinarian 29 4

Company service person 88 61

Occasional worker (e.g., family member, 

part time help over holiday) 38 21

Any visitor enter the barn 100 68

Median minimum and maximum temperatures in the barn 

during the 14-day defined risk period?

Minimum 55 61

Maximum 65 69

Median distance this barn (in yards) from:

Dead bird disposal/holding area including carcass bin for 

rendering 59 100

Litter compost (for barns where litter is composted) 50 100

Nearest road 100 100
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

20 USDA APHIS VS – For Internal Use Only 

C. References

USDA–APHIS. Epidemiologic and other analyses of HPAI-affected poultry flocks: September 9, 2015. Appendix 

B. HPAI Case Control Questionnaire – Layers. Available at 

https://www.aphis.usda.gov/animal_health/animal_dis_spec/poultry/downloads/Epidemiologic-AnalysisSept-2015.pdf

McQuiston, J. H., L. P. Garber, B. A. Porter-Spalding, J. W. Hahn, F. W. Pierson, S. H.Wainwright, D. A. Senne, T. 

J. Brignole, B. L. Akey, and T. J. Holt, 2005. Evaluation of risk factors for the spread of low pathogenicity 

H7N2 avian influenza virus among commercial poultry farm. J. Am. Vet. Med. Assoc. 226:767–772. 2005.
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 21

VI. PRELIMINARY ASSESSMENT OF HPAI 2016 MORTALITY SHEET DATA - NEW

Data from daily mortality sheets recorded in individual turkey barns were submitted for analysis 

from one H7N8 HPAI-affected farm (with four barns) and eight H7N8 LPAI-affected farms (with 26 

barns). These farms and barns were detected during the 2016 HPAI outbreak in Indiana. In addition, 

data were collected from 28* control farms (77 barns) during a similar period in the HPAI control 

area. 

The daily mortality data were used to obtain weekly mortality rates per barn, which were combined 

to obtain average weekly mortality rates per farm for case farms as well as control farms. High 

mortality was observed during the first 2 weeks after placement in many of the barns. This mortality 

was not likely associated with avian influenza. Consequently, the first 2 weeks of mortality data for 

each barn, post placement, were excluded from further analyses. 

The mean average mortality rate by week of the case farms and control farms was calculated to 

compare the mortality rates over the time frame of weeks 15W37 through 16W02 (September 7, 

2015 – January 17, 2016) to look for potential case farm risk weeks identified by the mortality rates. 

A. Findings

The median averaged farm mortality rates for case farms were compared to control farms. The 

pattern of averaged farm mortality rates between the case farms and control farms did not differ 

dramatically, except during the weeks of 15W41 (October 5 – 11, 2015) and 15W42 (October 12 –

18, 2015), with case farms demonstrating an average mortality rate that was 0.9 percent and 1.1 

percent higher, respectively, for those weeks. Also, during the week of 15W46 (November 9 – 15, 

2015), case farms demonstrated an average mortality rate that was 0.36 percent higher for that 

week (Figure 11). 

Figure 11. Median farm mortality rates by week

Seven of the eight H7N8 LPAI-affected farms noted a gradual slight increase in mortality rates during 

the last 1 to 2 weeks of the time period when turkeys were present on the farms (i.e., from 

approximately January 11 through January 15, 2016). Generally, however, mortality remained below 

0.3 percent during that time. On the H7N8 HPAI-affected farm, the unaffected barns showed a 

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Farm level median percent mortality

Median farm mortality rates by week: 

15W35 to 16W02 [September 7, 2015 – January 17, 2016]

H7N8 HPAI (n=1) and H7N8 LPAI affected turkey farms (n=8) [red line]

compared to Control turkey farms (n=28) [blue line] located in HPAI control area 

Case farms

Control farms
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

22 USDA APHIS VS – For Internal Use Only 

similar pattern as the H7N8 LPAI farms during the last 1 to 2 weeks, whereas the HPAI-affected barn 

itself peaked on January 15, 2016, at 19.20 percent mortality. A number of control farms/barns also 

exhibited an apparent pattern of increasing mortality rates during weeks of December 2015 and 

January 2016 (22/28, 75 percent).

B. Discussion

This preliminary comparison of mortality patterns did not adjust for age of the birds in the barns.

Further analysis is needed to account for differences in mortality that may have occurred related to 

the age of birds. The spike in mortality of the HPAI-infected farm did trigger a response. APHIS 

emergency management plans state that investigations should be conducted on daily mortality 

exceeding 0.1 percent or weekly mortality exceeding 1 percent4

. In “tom” flocks, mortality gradually 

increases after 16 weeks and may reach 1 percent per week by the time they are processed, which 

was seen in the case and control flocks. Extremely high daily mortality (>1/100) constitutes an 

emergency and should be reported and investigated to rule out the possibility of a foreign animal 

disease.

At this time, the importance of the mortality differences seen in October and November is 

uncertain. Although the relationship between this spike in mortality and LPAI is unknown, it may 

have been a predisposing factor. This mortality pattern difference between LPAI infected and 

uninfected premises was unexpected, especially in comparison to similar mortality patterns, as was 

noted, beginning November 16, 2015.

C. Next steps

1. APHIS plans to conduct more detailed analyses, including age-adjusted analyses of the weekly 

mortality rates by barns.

2. Water consumption per barn will be evaluated, comparing consumption in barns on case farms 

to control farms.

*For this preliminary review, submissions of mortality sheets were interpretable for use from 28/30 

control farms.

 4 Emergency Management Plans

[https://www.aphis.usda.gov/animal_health/emergency_management/.../poultry_ind_manual.pdf]
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 23

VII.ON-FARM SAMPLING: PRELIMINARY REPORT - UPDATED

Sampling for Influenza A Virus in Synanthropic Wildlife at Infected Premises

A. Objective

To evaluate the potential for synanthropic wildlife associated with commercial turkey flocks to 

become exposed or infected with highly pathogenic or low pathogenic influenza A (H7N8) viruses, 

USDA-APHIS Wildlife Services sampled peri-domestic birds and mammals on farms that had been

infected with an H7N8 influenza A virus.

Four farms with confirmed H7N8 infections were investigated (Table 8). All flocks were located in 

southern Indiana. Sampling at confirmed infected sites was conducted within 2 weeks after viral 

excretion was confirmed in poultry. Three of the four infected flocks were depopulated prior to 

wildlife sampling and one of the flocks was being depopulated during sampling.

Table 8. Summary of Infected Flocks

Site

Approximate

Flock Size Virus

Date H7N8 

Confirmed by NVSL

Wildlife Sampling 

Period

DuBois8 36,695 Low Pathogenic 1/16/2016 1/20-23/2016

DuBois1 62,109 Highly Pathogenic 1/14/2016 1/25-27/2016

DuBois9 16,591 Low Pathogenic 1/16/2016 1/28-29/2016

DuBois6 24,732 Low Pathogenic 1/16/2016 1/30/2016

B. Sampling Procedures

We captured wild birds and wild mammals on farms, primarily around farm structures. Birds were 

captured using mist nets and baited funnel traps. Mammals were trapped using baited collapsible 

Sherman traps (mice) and baited Tomahawk traps. We also collected environmental samples in and 

around feed hoppers and barns.

Captured individuals were sampled to test for infection with influenza A viruses (IAV) by collecting 

swabs, washes, and tissues. Prior exposures were also investigated by testing serum. From birds, we 

collected an oral swab and a cloacal swab. From targeted avian species (e.g., European starlings), we 

also collected a blood sample and lung tissue. From mammals, we collected an oral swab, nasal 

swab/wash, and external swab. From targeted mammalian species, we also collected a blood 

sample and lung tissue sample. Swabs, washes, and tissue samples were placed in 1-3mL of viral 

transport media and stored chilled. Blood was collected into serum separator tubes, allowed to clot, 

and centrifuged. We shipped samples overnight on ice to testing laboratories within 24 hours during 

the week or stored them in a refrigerator and then shipped overnight on ice.

C. Laboratory Procedures

Swabs, washes, and tissue samples were screened for influenza A virus (IAV) matrix gene RNA via 

real-time reverse transcriptase polymerase chain reaction (RRT-PCR). The Avian Veterinary 

Diagnostic Laboratory at Colorado State University conducted matrix gene RRT-PCR testing of avian 

oral and cloacal swabs, while the National Wildlife Research Center Virology Laboratory conducted 

all other matrix gene RRT-PCR. Per the National Animal Health Laboratory Network (NAHLN) 

protocol, any cycle threshold (Ct) value >0 was considered positive for viral RNA. Samples with Ct>0 

by matrix gene RRT-PCR were submitted to the USDA’s NVSL in Ames, IA, for confirmatory testing. 

Confirmatory testing included subtype confirmation using H5 and H7 assays targeting American 
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

24 USDA APHIS VS – For Internal Use Only 

lineage viruses. All serum samples were screened for antibodies to influenza A using the IDEXX AI 

Multi-S Screen Ab test, which is a multi-species blocking enzyme linked immunosorbent assay 

(ELISA) targeting an epitope of the nucleoprotein. All serum samples with S/N ratios <0.7 were 

submitted to NVSL for hemagglutinin inhibition (HI) assay testing using the H7N8 virus as the 

antigen.

D. Results

Across the four sampled farms, we collected 297 samples from 81 individuals (primarily starlings; 

Table 9). We sampled 77 individual birds across four species and four individual mammals across 

three species (Table 10). European starlings were the most commonly sampled species. We also 

collected 40 environmental samples, of which all but four were presumed to be from European 

starlings.

PCR testing for all oral and cloacal swabs, tissues, and environmental samples is complete and all 

samples were negative. ELISA testing for all serum samples has been completed. No samples were 

positive for antibodies to influenza A virus, but three samples were suspect positive (S/N ratio 

between 0.5-0.7). These samples were submitted to NVSL for H7 specific HI testing and were 

negative (Table 11).

Table 9. Summary of Samples Collected

Sample Type Total Number Collected

Number Collected 

from Birds

Number Collected from 

Mammals

Serum 65 62 2

Oral Swab 81 77 4

Cloacal Swab 77 77 --

Nasal Swab/Wash 4 -- 4

External Swab 2 -- 2

Lung Tissue 67 63 3

Environmental 40 38 2

Table 10. Summary of Animals Sampled

Species Scientific Name Numbered Sampled

House mouse Mus musculus 2

White-tailed deer Odocoileus virginianus 1

Raccoon Procyon lotor 1

European starling Sturnus vulgaris 63

Dark-eyed junco Junco hyemalis 8

White-throated sparrow Zonotrichia albicollis 4

Song sparrow Melospiza melodia 2

Table 11. Summary of positive samples for avian serum samples tested by ELISA

Sample Species ELISA S/N Ratio HI

IDa01020 European starling Suspect Positive 0.66 Negative

IDa01026 ` Suspect Positive 0.68 Negative

IDa01027 European starling Suspect Positive 0.61 Negative
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 25

E. Summary

No wildlife samples from animals associated with infected premises showed evidence of influenza 

infection or exposure. However, several important observations were noted among the sampled 

farms. First, the high levels of ammonia associated with depopulation and composting likely lowered 

mouse populations in turkey barns and undoubtedly influenced the number of mice captured. 

Second, weather patterns appeared to influence bird capture success, as the bulk of the starlings 

sampled in this survey were captured when temperatures were unseasonably low and snow was on 

the ground. Capture success was greatly reduced at subsequent farms when snow was largely 

absent and European starlings moved to cornfields. Third, spilled feed from grain hoppers appeared 

to be a key factor attracting wildlife to the single farm that had multiple feed spills due to feed 

hopper tubing breaches. Fourth, forest birds made up the majority of wildlife observed in proximity 

to the farms but they did not spend time in close proximity to barns. Fifth, relatively low numbers of 

wildlife captures were expected during the winter months due to altered ecology during that season 

resulting in differing resource use of farms (wildlife farm visits may be sporadic, especially for birds), 

annual mortality (many animal populations are lowest during the winter), reduced resources, lack of 

breeding, and minimal movements. 

It is clear that these factors contribute to the episodic use of poultry farms by wildlife, especially 

during the winter months. This periodic use of farms by wildlife undoubtedly contributed to low 

capture rates. As such, considering that the prevalence of IAV in the natural wildlife reservoir (i.e., 

waterfowl and aquatic birds) is relatively low during most time frames, it is a reasonable assumption 

that the natural prevalence in bridge species (synanthropic avian and mammalian species such as 

European starlings, mice, and skunks) is even lower. Therefore, detection of infection in these 

species is a challenging task even when the animals are relatively common on farmsteads. Although 

no positive wildlife species were detected within close proximity to farms in Indiana, the potential 

role of wildlife in the IAV case clusters of DuBois County should not be discounted. For example, 

following the HPAI outbreaks in Iowa, a PCR-positive European starling (lung tissue) and several 

avian species that were antibody-positive for HP H5N2 AIV were discovered. However, the avian 

populations at the Iowa sites, in general, were more diverse and more stable when compared to 

those sampled in Indiana.

Anecdotally, several owners of the sampled premises reported the presence of large numbers of 

European starlings and/or Canada geese (on some farms) prior to the outbreaks. Consequently, we 

plan to experimentally inoculate starlings and possibly geese with the H7N8 viruses to determine if 

these species can host these strains and shed viruses at levels that are epidemiologically significant.

This effort highlights the need to survey multiple poultry facilities in several regions of the United 

States to assess wildlife interactions with poultry facilities. Similar studies in Canada have been used 

to inform risk assessments and to develop lists of key species of concern. A comparable approach in 

the United States could be used to develop lists of key wildlife species of concern to the poultry 

industry. Once developed, a species list could guide experimental infection studies to assess the 

reservoir competence of select synanthropic wildlife species.

F. Acknowledgements

We greatly appreciate the cooperation and support of the poultry industry for allowing us access to 

their properties.
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

26 USDA APHIS VS – For Internal Use Only 

VIII. LITERATURE REVIEW 

A. Latent and Infectious Periods for H7 HPAI Virus Strains

Background

The following is a brief summary of the latent and infectious period data for chickens and turkeys 

from literature review as well as unpublished data shared by the Southeast Poultry Research 

Laboratory in Athens, GA. The statistical distributions estimated from these data are useful for 

disease spread modelling and for evaluating the impact of various surveillance and movement 

protocols. Many of the analyses conducted to support emergency response and business continuity 

measures have been based on the latent and infectious periods for H5 HPAI viruses. The purpose of 

this review was to evaluate whether the latent and infectious periods for chickens and turkeys 

infected with H7 HPAI viruses differed greatly from what has been seen with H5 HPAI viruses. 

Bird-level infectious period and mean time to death for H7 HPAI

There is considerable variability in the estimated infectious period for different H7 HPAI strains. The 

mean infectious period estimate was 6.3 days for Netherlands H7N7 HPAI in chickens (Table 12). 

Given the available data, only the mean time to death could be estimated for the Jalisco H7N3 HPAI

strain. The mean time to death in chickens for this strain was around 2.3 days and suggests a shorter 

infectious period compared to the Netherlands strain.

In turkeys, the estimated infectious period was 6.2 days for the Netherlands H7N7 HPAI strain and 

1.47 days for the Italy H7N1 HPAI strain. The mean time to death for the Mexico H7N3 HPAI strain in 

turkeys was 2.47 days.

Table 12. Summary of infectious period and time to death data for H7 HPAI strains

HPAI strain Source Species

Parameter 

estimated

Estimated value /

Distribution Days

H7N3 HPAI Mexico Unpublished data (Erica 

Spackman)

Turkeys Time to 

death

2.47 days (95% C.I., 0.9-

4.92). Gamma (5.96,0.41)

H7N3 HPAI Mexico Unpublished data.

Kapczynski (personal 

communication)

Chickens Time to 

death

1.9 (95% C.I., 0.9-4.92), 

Gamma (10.7,.18)

H7N3 HPAI Mexico Bertran 2013; Kapczynski et 

al 2013; Spackman et al 

2014. [1-3]

Chickens Time to 

death

2.25; 2.3 

H7N7 HPAI 

Netherlands

Vandergoot et al 2005 [4] Chickens Infectious 

period

6.3(95% C.I., 3.9-8.7)

H7N7 HPAI

Netherlands

Bos et al 2008 [5] Turkeys Infectious 

period

6.2 days (range 5-8)

H7N7 HPAI 

Netherlands

White paper- Templeton et 

al, Maas et al 2009 [6]

Chicken Time to 

death

5.1 (95% C.I. 3.5-6.9);

H7N7 HPAI 

Netherlands

CEAH analysis [4, 6] Chicken Infectious 

period

4.1 (95% C.I. 2.3-5.6); 

Gamma (5.738, 5.445)

H7N1 HPAI Italy Saenz et al 2012 [7] Turkeys Infectious 

period

1.47 (95% C.I., .3-3); Gamma 

(2.199,1.668)
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 27

Bird-level latently infected period

The estimated mean latent period in turkeys was 0.8 days for Netherlands HPAI H7N7 and 0.4 days 

for Italy H7N1 HPAI strain (Table 13). 

For chickens, the available experimental data was censored with testing for shedding at daily 

intervals. However, for both the Mexico H7N3 HPAI strain and Netherlands H7N1 HPAI strains, the 

inoculated chicken were shedding by the first day indicating a short latent period.

Table 13. Summary of bird-level latent period data for H7 HPAI strains

HPAI strain Source Species

H7N3 HPAI Mexico Kapczynski et al (personal 

communication)

Between 0-1 days: 5 chickens inoculated, all were shedding 

within 24 hours; 

H7N7 HPAI

Netherlands

Vandergoot et al 2005 [4] Between 0-1 days: 10 chickens inoculated, all were shedding 

within 24 hours;

H7N7 HPAI 

Netherlands

Bos et al 2008 [5] 0.7 days: 8/10 turkeys were shedding by 1 day and 2/10 

turkeys by 2 days. Gamma (17.08, 0.04)

H7N1 HPAI Italy Saenz et al., 2012 [7] Mean 0.40 days: based on 10 inoculated turkeys. Suggested 

gamma distribution (Gamma 2.2,0.186)

Summary and implications for current outbreak 

The infectious and latent period distribution data was summarized for three H7 HPAI strains. 

Overall, the infectious period was short (1.5-2.5 days) for H7N3 HPAI and H7N1 HPAI strains 

compared to Netherlands H7N7 HPAI strain, which had an infectious period around 6 days. The data 

indicate a short latent period (less than 1 day) for all the three strains summarized. These results are 

similar to the infectious and latent period distributions identified during the 2015 outbreak of HPAI 

in the United States.

These results suggest that the assumptions related to bird-level viral transmission dynamics used for 

modeling work and analysis based on the U.S. HPAI outbreak in 2015 are still appropriate for an 

outbreak involving a highly pathogenic H7 virus. 

B. Predominant Clinical Signs in Turkeys for Recent Outbreaks of H5 or H7 HPAI virus 

strains

Background

The presence and severity of clinical signs of HPAI infection depend on the type of bird species 

affected. Infected wild and domestic ducks may be asymptomatic, whereas clinical signs in 

gallinaceous poultry are usually severe, resulting in high mortality. In poultry (chickens and turkeys), 

the clinical signs associated with HPAI infection include marked depression with ruffled feathers, 

lack of appetite, excessive thirst, decreased egg production, soft-shelled or misshaped eggs, 

respiratory signs (coughing and sneezing), watery diarrhea, or sudden, unexpected death. In turkeys, 

a cessation in flock vocalization (Cathedral Syndrome) often accompanies infection. Mature chickens 

frequently have swollen, cyanotic combs and wattles and edema surrounding the eyes. 

The mortality rate in an infected flock can reach 100 percent. In mature birds, gross lesions on 

necropsy may consist of subcutaneous edema of the head and neck; fluid in the nares, oral cavity, 

and trachea; congested conjunctivae and kidneys; and petechial hemorrhages that cover the 

abdominal fat, serosal surfaces, peritoneum, and surface under the keel. In layers, the ovary may be 
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

28 USDA APHIS VS – For Internal Use Only 

hemorrhagic or degenerated and necrotic. The peritoneal cavity is frequently filled with yolk from 

ruptured ova, causing severe airsacculitis and peritonitis in birds that survive longer than 7 days. In 

addition, necropsy of birds affected in the 1999–2001 H7N1 HPAI outbreak in Italy revealed 

pancreatitis in all species of birds; this was most pronounced in turkeys and chickens.[8]

Clinical signs in turkeys

Clinical signs for HPAI infection in turkeys are different from those in chickens. Moreover, they vary 

depending on the HPAI virus strain (see Table 14). Respiratory signs may not be present in turkeys 

infected with HPAI, and producers should watch for other symptoms including neurological signs.

Table 14. Summary of primary clinical signs seen in turkeys during recent outbreaks by HPAI strain

HPAI Strain Clinical signs Source

H7N1 Nervous signs Mutinelli et al., 2003 [8]

H5N8 Depression, loss of balance, drooping of wings, 

twitching McNulty et al., 1985 [9]

H7N7 Apathy, reduced vocalization, swollen sinuses, mucus 

from beak, lying down with neck extended Elbers et al., 2004 [10]

H5N1 Attenuated motor functions, torticollis and 

nystagmus, general behavioral aberrations Perkins and Swayne, 2001 [11]

H5N1 Reluctance to move, facial oedema, sinusitis, oculonasal discharge, and haemorrhages on the shanks Kilany et al., 2011 [12]

H5N1 Depressed, quiet flock, nearly all sitting down, 

apathy, fine head tremors Irvine et al., 2007 [13]

H5N9 Depressed, wings dropped, diarrhea, abnormal 

respiration was not seen, listless Narayan, Lang and Rouse 1969 [14]

H5N2 Lethargy, depressed, lack of vocalization neurological 

signs, occasional torticollis and blood from the mouth

2015 US Outbreak Reports

C. References

1. Bertran, K., et al., Protection against H7N3 high pathogenicity avian influenza in chickens immunized with 

a recombinant fowlpox and an inactivated avian influenza vaccines. Vaccine, 2013. 31(35): p. 3572-3576.

2. Kapczynski, D.R., et al., Characterization of the 2012 highly pathogenic avian influenza H7N3 virus isolated 

from poultry in an outbreak in Mexico: pathobiology and vaccine protection. Journal of virology, 2013. 

87(16): p. 9086-9096.

3. Spackman, E., et al., Potency, efficacy, and antigenic mapping of H7 avian influenza virus vaccines against 

the 2012 H7N3 highly pathogenic avian influenza virus from Mexico. Avian diseases, 2014. 58(3): p. 359-

366.

4. van der Goot, J.A., et al., Quantification of the Effect of Vaccination on Transmission of Avian Influenza 

(H7N7) in Chickens. Proceedings of the National Academy of Sciences of the United States of America, 

2005. 102(50): p. 18141-18146.

5. Bos, M.E., et al., Effect of H7N1 vaccination on highly pathogenic avian influenza H7N7 virus transmission 

in turkeys. Vaccine, 2008. 26(50): p. 6322-8.

6. Maas, R., et al., Dose response effects of avian influenza (H7N7) vaccination of chickens: Serology, clinical 

protection and reduction of virus excretion. Vaccine, 2009. 27(27): p. 3592-3597.

7. Saenz, R.A., et al., Quantifying Transmission of Highly Pathogenic and Low Pathogenicity H7N1 Avian 

Influenza in Turkeys. PLoS ONE, 2012. 7(9): p. e45059.

8. Mutinelli, E., et al., Clinical, Gross, and Microscopic Findings in Different Avian Species Naturally Infected 

During the H7n1 Low- and High-Pathogenicity Avian Influenza Epidemics in Italy During 1999 and 2000. 

Avian Diseases, 2003. 47: p. 844-848.
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 29

9. McNulty, M.S., et al., Isolation of a highly pathogenic influenza virus from turkeys. Avian Pathol, 1985. 

14(1): p. 173-6.

10. Elbers, A.R.W., et al., The highly pathogenic avian influenza A (H7N7) virus epidemic in the Netherlands in 

2003 - Lessons learned from the first five outbreaks. Avian diseases, 2004. 48(3): p. 691-705.

11. Perkins, L.E. and D.E. Swayne, Pathobiology of A/chicken/Hong Kong/220/97 (H5N1) avian influenza virus 

in seven gallinaceous species. Vet Pathol, 2001. 38(2): p. 149-64.

12. Kilany, W.H., et al., Protective efficacy of H5 inactivated vaccines in meat turkey poults after challenge 

with Egyptian variant highly pathogenic avian influenza H5N1 virus. Vet Microbiol, 2011. 150(1-2): p. 

28-34.

13. Irvine, R.M., et al., Outbreak of highly pathogenic avian influenza caused by Asian lineage H5N1 virus in 

turkeys in Great Britain in January 2007. Vet Rec, 2007. 161(3): p. 100-1.

14. Narayan, O., G. Lang, and B.T. Rouse, A new influenza A virus infection in turkeys. V. Pathology of the 

experimental disease by strain turkey-Ontario 7732-66. Arch Gesamte Virusforsch, 1969. 26(1): p. 166-82.
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

30 USDA APHIS VS – For Internal Use Only 

APPENDIX A. FARM-LEVEL QUESTIONS - UPDATED

Characteristic Percent case farms Percent control farms

Farm size (number of birds on farm on 

reference date):

Less than 20,000 44 55

20,000 or more 56 45

Number of barns on the farm:

1 - 3 44 67

4 or more 56 33

Marketing arrangement:

Contract 100 97

Other 0 3

Stage of production:

Brooder 33 62

Grower 100 93

Breeders 0 0

Other 0 0

If both grower and brooder:

In barn at same time 0 0

In same barn but at different times 

(e.g., placed as brooders and remain 

through grow-out)

0 0

In different barns 100 100

Birds have outside access 0 3

Sex of market type:

Hens (HH or LH) 0 10

Toms (FP) 100 87

Both hens and toms 0 3

Age of birds on farm:

Multiple 22 57

Single 78 43

Other poultry on farm (e.g., broilers, layers, 

etc.) 0 0

Certified Organic 0 0

Enrolled in NPIP 100 97

Water bodies within 350 yards: 100 77

Pond 100 60

Lake 0 10

Stream 0 31

River 11 7

Wetland or swamp 0 3

Wastewater lagoon 0 3

Other 0 7
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 31

Characteristic Percent case farms Percent control farms

Waterfowl seen on the above water bodies 

during the 14-day defined risk period: 

Ducks 11 7

Geese 0 7

Shorebirds 22 10

Other 0 3

Distance (yds.) to the closest field where 

crops or hay are harvested:

Less than 50 67 57

50 to 99 22 17

100 or more 11 27

Crop grown in the above field:

Corn 56 48

Soybeans 22 34

Alfalfa/grass 22 17

Other 0 0

Above field tilled last fall 33 28

Above field actively worked during the 14-

day defined risk period: 0 3

Waterfowl seen on the field during the 14-

day defined risk period: 0 16

Other animals present on farm premises:

Beef cattle 44 40

Dairy cattle 0 0

Horses 0 10

Sheep 0 3

Goats 0 3

Pigs 0 13

Dogs 33 30

Cats 44 30

Poultry or domestic waterfowl 

(noncommercial) 0 3

Other 0 7

Water source for poultry:

Municipal 100 93

Well 11 7

Surface 0 0

Other 0 0

Water treatments:

Chlorination (excluding municipal) 0/1 2/2

Acidifiers 0 14

Iodine 11 60

Peroxide 11 27

Other 0 10

Windbreaks present on farm:
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

32 USDA APHIS VS – For Internal Use Only 

Characteristic Percent case farms Percent control farms

Evergreen or juniper 0 0

Deciduous trees 44 43

Structural (e.g., hill, natural break) 11 20

Distance to nearest public gravel or dirt 

road, excluding driveways (yds.):

Less than 100 22 20

100 to 499 33 40

500 or more 44 40

Direction from public road to farm:

East/NE/SE 56 27

House with people living in it on the 

property

44 37

If yes, common drive entrance to farm and 

residence 100 64

More than one entrance to the farm that 

could provide access to the poultry area 13 41

Road surface on the farm that vehicles 

coming onto the operation drive on:

Hard top/asphalt 0 21

Gravel 89 76

Dirt 0 0

Other 11 3

Access of the following vehicles:

Perimeter

only

Enter 

farm/

not 

near 

barn

Near 

barn

Does 

not 

come

Perimeter 

only

Enter 

farm/

not 

near 

barn

Near 

barn

Does 

not 

come

Garbage/dumpster pickup 11 0 11 78 7 13 7 73

Propane delivery 11 11 22 56 0 3 83 13

Feed delivery 0 0 100 0 0 3 97 0

Renderer 0 0 0 100 0 0 0 100

Company personnel 11 0 89 0 0 7 93 0

Other business visitors 22 11 56 11 0 0 60 40

Has gate to farm entrance 0 30

Perimeter surrounded by security fence 0 7

Vegetation mowed/bush hogged at least 3 

times per month 100 89

Vehicle wash station/spray area used 

during the 14-day defined risk period 0 20

Workers and visitors park in restricted area 

away from the poultry barns during the 14-

day defined risk period: Always

Sometimes Never AlwaysSometimes Never

Workers 78 22 0 13 0 87

Visitors 33 33 33 7 3 90

Rat/mouse bait stations used on the farm 

during the 14-day defined risk period 89 100
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 33

Characteristic Percent case farms Percent control farms

If yes, frequency checked 

(times/month):

Less often than 1 14 10

1 71 63

2 or more 14 27

Frequency rodents observed during the 14-

day defined risk period:

Frequently (e.g., daily) 13 0

Occasionally (e.g., weekly) 13 31

Never 75 69

Beetle control used during the 14-day 

defined risk period: 11 47

Beetles observed in poultry barns during 

the 14-day defined risk period: 50 52

Fly control (other than manure removal) 

used during the 14-day defined risk period 0 7

Intensity of flies observed in poultry barns 

during the 14-day defined risk period:

High 0 3

Medium 0 7

Low/none 100 90

Wild mammals (or evidence) observed in or 

around poultry barns during the 14-day 

defined risk period

88 41

Access to poultry feed:

Wild birds 38 10

Wild animals 38 10

Rodents 25 3

Pelleted feed 100 100

Feed treatment:

Formaldehyde 0 0

Heat treated 100 100

Within 100 yards of barns: Often

Sometimes Never OftenSometimes Never

Waterfowl 0 25 75 3 17 79

Gulls 11 0 89 0 0 100

Small perching birds 25 50 25 48 41 10

Blackbirds/crows 13 50 37 45 34 21

Other water birds 0 13 87 0 0 100

Wild turkeys, pheasants, quail 13 13 75 0 10 90

Raptors 0 38 62 3 24 72

Pigeons/doves 0 0 100 10 21 69

Other 0 0 100 0 0 100

In the barn:

Large birds (pigeons, crows) 0 0 100 0 0 100
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

34 USDA APHIS VS – For Internal Use Only 

Characteristic Percent case farms Percent control farms

Small birds (finches, sparrows, 

starlings) 0 0 100 0 14 86

Other 0 0 100 0 0 100

Dead birds:

Inside the barn 0 0

Outside the barn 0 7

Number of employees:

1 38 7

2 25 29

3 or more 38 64

Frequency measures were required for 

workers entering the barns during the 14-

day risk period: Always

Sometimes Never AlwaysSometimes Never

Establish clean/dirty line 100 0 0 93 0 7

Shower 13 0 87 0 3 97

Wash hands/hand sanitizer 37 13 50 27 17 57

Different personnel for different barns 0 0 100 13 10 77

Disposable coveralls 25 0 75 23 0 77

Change clothing 62 0 38 13 13 73

Change shoes/shoe covers 100 0 0 97 3 0

Liquid foot bath 100 0 0 83 0 17

Dry foot bath 0 0 100 18 0 82

Scrub footwear 37 0 63 37 27 37

Workers on the farm:

Work on other company farms 50 50

Employed by other poultry operations 13 17

Own their own poultry 0 7

Required to stay off farm at least 24 h 

after exposure to other poultry 13 0

Visitor log used 71 41

Visitor type during the 14-day risk period: Visitors

Avg # 

times

Entered 

barn Visitors

Avg # 

times

Entered 

barn

Federal/State veterinary or animal 

health worker 0 0

Extension agent or university 

veterinarian 13 0 0

Private or company veterinarian 13 2 25 0

Company service person 88 2 88 72 2 57

Nutritionist or feed company 

consultant 0 0

Bird delivery personnel 0 10 1 0

Vaccination crew 0 0

Catch crew (bird removal) 25 1 14 7 1 10

Feed delivery personnel 88 8 13 97 4 8

Egg truck personnel (for breeder farms) 0 0
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 35

Characteristic Percent case farms Percent control farms

Litter delivery services 13 1 0 23 2 3

Litter removal services (e.g., litter 

broker, litter disposal) 0 0

Customer (private individual) 0 0

Wholesaler, buyer, or dealer 0 0

Renderer 0 0

Occasional worker (e.g., family 

member, part-time help over holiday) 50 8 38 23 2 20

Construction workers, repair or 

maintenance person 0 3 1 0

Other business visitors (including 

other producers, meter readers, 

package delivery (UPS), etc.)

25 1 13 20 1 0

Other nonbusiness visitors 

(including neighbors, friends, family 

members, and school field trips)

14 14 0 7 3 0

Any visitors enter the barn 100 57

Requirements for visitors who entered the 

barn during the 14-day risk period:

Yes; 

verified at 

farm

Yes; visitor 

responsibility No

Yes; 

verified at 

farm

Yes; visitor 

responsibility No

Change outer clothing 75 25 0 25 46 29

Foot covers or change footwear 75 25 0 37 42 21

Mask 37 0 63 13 4 83

Hand sanitizer or gloves 75 25 0 30 39 30

Not visit multiple farms in the same day 0 0 100 4 8 88

Other 0 0 100 0 4 96

Shared the following vehicles with another 

farm during the 14-day defined risk period:

Company trucks/trailers (e.g., pickup 

truck, trailer with supplies, supervisor 

truck)

100 86

Feed trucks 100 90

Bird delivery (i.e., placing birds) 0 20

Bird removal 11 17

Egg removal (for breeder farms) 0 0

Manure/litter hauling 0 10

ATV/4-wheeler 22 7

Other 0 10

Equipment 11 40

Litter heat treated 33 27

Litter storage: 78 40

Outside 0 10

Closed shed 33 13

Open shed 44 23

Stored less than 30 yards from barn 60 73

Stored litter accessible to:

Wild birds 57 58
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

36 USDA APHIS VS – For Internal Use Only 

Characteristic Percent case farms Percent control farms

Wild animals 57 58

Domestic animals 57 58

Litter disposal method:

Composted on-farm 33 11

Stored on-farm 11 11

Applied to land on farm 11 15

Taken off-site 89 76

Manure or used litter from other farms 

spread on this farm 0 3

Normal daily mortality (%):

Less than 0.2 100 89

0.2 or more 0 11

Dead bird (daily mortality) disposal 

method:

Composting on farm 67 90

Burial 0 0

Incineration 11 0

Rendering 0 0

Landfill 0 0

Other off-farm 22 10

If compost or burial, cover with:

Soil 0 7

Manure 100 78

Sawdust 0 7

Wild birds or wild mammals observed 

around the dead bird collection area during 

the 14-day risk period:

Wild birds 63 61

Wild mammals 50 50

Common (off-farm) collection point for 

dead bird disposal 33 31
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 37

APPENDIX B. BARN-LEVEL QUESTIONS - UPDATED

Percentage of barns by barn characteristics

Characteristic Percent case barns Percent control barns

Type(s) of poultry present in this barn:

Brooder 0 26

Grower toms 100 74

Grower hens 0 4

Breeders 0 0

Other 0 0

Birds in this barn have outside access 11 0

Number of birds placed in this barn:

Fewer than 4,000 0 4

4,000 to 9,999 100 64

10,000 or more 0 32

Length of time birds in barn (weeks):

Less than 4 0 26

4 to less than 8 25 33

8 to less than 12 38 15

12 or more 38 26

Age of birds (weeks):

Less than 8 0 44

8 to less than 14 25 15

14 or more 75 41

Different stages of production (e.g., brooders and growers) 

present in this barn at the same time 11 0

Another health concern in this flock during the defined risk 

period 44 11

Flock being treated for a condition or health concern during 

the defined risk period 44 18

Age of barn structure (yrs.):

Less than 5 0 4

5 to less than 10 11 25

10 or more 89 71

For barns more than 5 years old, last remodeled within 5 years 78 22

How well the barn structure has been maintained:

1. Well (e.g., walls, curtains, and mud boards do not have 

holes, no visible daylight, the barn is tight and well 

insulated)

67 75

2. Moderate (e.g., barn could have rust or small holes, mud 

boards may be damaged, curtains may be torn or not in 

good repair, curtains may not close all the way, 

insulation may not be in good repair, the poly may be 

hanging from the ceiling)

33 25
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

38 USDA APHIS VS – For Internal Use Only 

Characteristic Percent case barns Percent control barns

3. Poor (e.g., holes in walls and mud boards are apparent, 

tin is rusted, may have leaks in roof, there might be some 

holes large enough for wild birds to enter, multiple areas 

with daylight visible, insulation may be hanging from the 

ceiling)

0 0

Type of ventilation used for this barn during the 14-day defined 

risk period 

Curtain ventilated 33 32

Environmental control/tunnel ventilation 56 54

Side doors (i.e., tip outs) 11 11

Other 0 4

Intake air filtered 0 0

Needed to repair or replace any feed tank lids in the past 14 

days 0 0

Any feed tank lids open in the past 14 days 0 0

Ground surface immediately surrounding (within 1 yard) this 

barn (excluding vehicle approach and loading area):

Gravel or hard surface 56 67

Dirt 0 7

Short grass 44 26

Tall grass or brush 0 0

Hard-surface entry pad (e.g., concrete, asphalt):

Cleaned and disinfected 33 68

Cleaned only 11 14

Not cleaned or disinfected 33 7

No hard-surface entry pad 22 11

Frequency the following 

were used in this barn during 

the 14-day defined risk 

period:

Used 

regularly

Not used 

regularly

Not 

available

Used 

regularly

Not used 

regularly

Not 

available pvalue

Locks on the doors 11 44 44 4 74 22 .25

A service room that 

personnel must enter 

through that separates 

“outside area” from 

“inside area”

100 0 0 86 0 14 .55

Changing area for 

employees 89 0 11 68 11 21 .41

A shower for employees 11 0 89 0 7 93

Cool cell pads 0 22 78 11 25 64 .55

Misters 0 89 11 0 48 52 .03

Type of footbath in use at this barn:

Dry (i.e., powdered or particulate) 0 18

Liquid 100 82

Other 0 0

None 0 0

Dry footbath changed at least 1x/week - 60
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 39

Characteristic Percent case barns Percent control barns

Liquid footbath changed at least 1x/day 0 0

Type of litter used in this barn:

Wood shavings 89 75

Hulls (e.g., oat, rice, sunflower, other) 11 25

Other 0 0

Litter is:

Bagged (i.e., baled) 0 4

Bulk (i.e., load from shavings mill) 100 96

Litter was “tilled” after it was placed in the barn 67 75

Litter was added to the barn during the defined risk period 0 12

Partial clean-out performed in this barn 

(during the 14-day defined risk period) 0 4

Last full clean-out:

Prior to this flock 67 68

Two flocks ago 22 21

Three or more flocks ago 11 11

If a full cleanout was performed, person who performed the 

full cleanout:

Grower 78 79

Contractor 22 21

Partial load-out occurred while this flock was present 0 7

Wild birds seen in this barn during the 14-day defined risk 

period 0 0

Types of people who entered this barn during the 14-day 

defined risk period:

Federal/State veterinary or animal health worker 0 0

Extension agent or university veterinarian 0 0

Private or company veterinarian 29 4

Company service person 88 61

Nutritionist or feed company consultant 0 0

Bird delivery personnel 0 0

Vaccination crew 0 0

Catch crew (bird removal) 0 0

Feed delivery personnel 0 7

Egg truck personnel (for breeder farms) 0 0

Litter delivery services 0 0

Litter removal services (e.g., litter broker, litter disposal) 0 0

Customer (private individual) 0 0

Wholesaler, buyer, or dealer 0 0

Renderer 0 0

Occasional worker (e.g., family member, part time help 

over holiday) 38 21

Construction workers, repair or maintenance person 0 0

Other business visitors (including other producers, meter 

readers, package delivery (UPS), etc.) 13 0
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

40 USDA APHIS VS – For Internal Use Only 

Characteristic Percent case barns Percent control barns

Other nonbusiness visitors (including neighbors, friends, 

family members, and school field trips) 0 0

Any visitor enter the barn 100 68

If controller information is available median percentage of time 

that curtains were open and median numbers of days open or 

partially open during the defined risk period:

% time 0 0

# days 0 0

Median minimum and maximum temperatures in the barn 

during the 14-day defined risk period?

Minimum 55 61

Maximum 65 69

Median distance this barn (in yards) from:

Dead bird disposal/holding area including carcass bin for 

rendering 59 100

Litter compost (for barns where litter is composted) 50 100

Nearest road 100 100
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS – For Internal Use Only 41

APPENDIX C. HPAI CASE CONTROL QUESTIONNAIRE

HPAI turkeys, version 4, January 15, 2016
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

42 USDA APHIS VS – For Internal Use Only 

Study ID: _______________ frmid

EMRS (premises) ID: ________________ premid

Date (mm/dd/yy): __________ date

Interviewer instruction: Bring satellite image of farm to interview. Enter Lat and Long at farm gate.

A. PREMISES INFORMATION

Farm name: ________________________________________________________________ frmname

Farm address: ______________________________________________________________ frmadd

County: ____________________________ frmcty Lat_________ lat Long_________long

1. Company flock supervisor name: ____________________________________________________ t101

Phone: _____________ t102 Cell phone: _________ t103 Email: _______________ t104

2. Farm manager contact name: ______________________________________________________ t105

Phone: _____________ t106 Cell phone: _________ t107 Email: ________________ t108

3. Flock veterinarian: ___________________________________________________________ t109

Phone: _____________ t110 Cell phone: _________ t111 Email: ________________ t112

B. INTERVIEWER INFORMATION

Interviewer name/organization: _________________________________________________ intrname

Interviewee name/organization: ________________________________________________ intename

Animal and Plant 

Health Inspection

Service

Veterinary Services

National Animal Health 

Monitoring System

2150 Centre Ave., Bldg B

Fort Collins, CO 80526

Form Approved

OMB Number 0579-0376

Approval Expires: 

9/30/2017

HPAI Case Control 

Questionnaire

Turkeys
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS 43

Study ID: _______________ frmid

Date (mm/dd/yy): __________ date

INSTRUCTIONS

State and local poultry organizations [fill in cooperators here] and the U.S. Department of Agriculture 

APHIS (USDA APHIS) are conducting a case-control study as part of the highly pathogenic avian 

influenza (HPAI) investigation efforts to identify factors that may contribute to transmission of H5N2 

influenza virus to poultry.

We are asking you to fill out this survey, which includes questions about things done daily on the 

farm, facility and premises condition, deliveries to the farm, and ill birds. We ask about a 2-week (14-

day) period on the farm starting on a particular date that we will provide. It might be difficult to 

remember back that far, so please use a pocket calendar or other agenda manager and any feed and 

other delivery records that might be available to you.

Term Case definition Control definition

Premises Farm location with flocks confirmed to be 

HPAI H5N2 infected by NVSL, including all 

barns and buildings, even if not all barns 

and buildings contain infected birds.

Turkey farm location with no infected birds in 

any barn or building, in close proximity (less 

than 10 miles) to the case farm. (If case farm is 

a turkey breeder, select a noninfected turkey 

breeder as the control.)

Barn Barn or building that houses HPAI H5N2-

infected birds.

On control premises, a barn or building that 

does not house any infected birds.

Dates of study focus:

Case farms answer questions for the timeframe of 14 days prior to the onset of clinical signs or increased 

mortality. All questions that ask about the “defined risk period” refer to this time period.

Control farms answer questions for the timeframe of 14 days prior to date of first detection on the matched 

case farm. All questions that ask about the “defined risk period” are referring to this time period.

National Animal Health 

Monitoring System

2150 Centre Ave., Bldg B

Fort Collins, CO 80526

Form Approved

OMB Number 0579-0376

Approval Expires: 

9/30/2017

Animal and Plant 

Health Inspection

Service

Veterinary Services

HPAI Case Control 

Questionnaire

Turkeys

According to the Paperwork Reduction Act of 1995, an agency may not conduct or sponsor, and a person is not

required to respond to a collection of information unless it displays a valid OMB control number. The valid OMB 

control number for this information collection is 0579-0376. The time required to complete this information collection 

is estimated to average 1 hour per response, including the time to review instructions, search existing data 

resources, gather the data needed, and complete and review the information collected.

NAHMS-348

SEP 2015
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

44 USDA APHIS VS

A. CASE OR CONTROL

1. Is this a case or control farm? t201

1 Case [Go to question 2.]

3 Control [Go to question 3.]

2. If this is a case farm,

a. When were clinical signs or increased mortality first observed?

This is what we will refer to as the reference date .............................................. t202 _______ mm/dd/yy

b. Enter the date 14 days prior to the date of first detection 

(clarifying timeframe of study focus) ........................................................................t203 _______ mm/dd/yy

All questions regarding the “defined risk period” refer to the 14 days 

prior to this reference date (i.e., the time between “a” and “b”).

c. How many birds were on this farm on this reference date?.....................................t204 _______ # birds

d. On the reference date, was this farm in an existing control zone? .... t205..................................1 Yes 3 No

e. When was the flock diagnosed as positive by laboratory confirmation? .................t206 _______ mm/dd/yy

f. As of today, how many of the barns on this farm have been 

confirmed or are suspected of being infected with HPAI?........................................t207 ______ # barns

[Go to section B.]

3. If this is a control farm, 

a. Enter reference date 

(enter date of matched case farm prior to interview) ..............................................t208 _______ mm/dd/yy

b. Enter the date 14 days prior to the reference date ..................................................t209 _________ mm/dd/yy

All questions regarding the “defined risk period” refer to the 14 days 

prior to this reference date (i.e., the time between “a” and “b”).

c. How many birds were on this farm on this reference date?.....................................t210 ________ # birds

d. Is this farm located in a control zone today? ............................................................t211 1 Yes 3 No

If Yes, how long has it been in a control zone? ...........................t212d/t212w _____ days OR _____ weeks
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS 45

B. PREMISES DESCRIPTION

1. Is this a: [Check one only.] t301

1 Company farm?

2 Contract farm?

3 Lease farm?

4 Independent farm?

2. What stage(s) of turkey production is on this farm?

a. Brooder............................................................................................................... t302 1 Yes 3 No

b. Grower................................................................................................................ t303 1 Yes 3 No

c. Breeder ............................................................................................................... t304 1 Yes 3 No

d. Other (specify: __________________________________) t305oth ...................... t305 1 Yes 3 No

[If question 2a OR question 2b = No, SKIP to question 4.]

3. Are brooders and growers: [Check one only.] t306

1 In the barn at the same time?

2 In the same barn but at different times (e.g., placed as brooders 

and remain through grow-out)?

3 In different barns? 

4. What is the sex of the market type on this farm? [Check one only.] t307

1 Hens (HH or LH)

2 Toms (FP)

3 Both hens and toms (i.e., multiple market classes)

4 Breeder hens

5 Breeder toms

5. Is this farm multiple age or single age? [Check one only.] t308

1 Multiple age

2 Single age

6. What other type(s) of poultry is present on this farm?

a. Broiler.................................................................................................................. t309 1 Yes 3 No

b. Layer.................................................................................................................... t310 1 Yes 3 No

c. Other (specify: ________________________________________) t311oth .......... t311 1 Yes 3 No
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

46 USDA APHIS VS

7. Is this farm certified organic?..................................................................................................t312 1 Yes 3 No

8. Is this facility enrolled in NPIP? ...............................................................................................t313 1 Yes 3 No

9. How many barns are on this farm? ........................................................................................t314 _____ # barns

10. Do any birds on the farm have access to the outdoors?.........................................................t315 1 Yes 3 No

11. Are the following water body type(s) visible or within 

350 yards (about three football fields) of this farm?

a. Pond .................................................................................................................................t316 1 Yes 3 No

b. Lake ..................................................................................................................................t317 1 Yes 3 No

c. Stream..............................................................................................................................t318 1 Yes 3 No

d. River .................................................................................................................................t319 1 Yes 3 No

e. Wetland or swamp ..........................................................................................................t320 1 Yes 3 No

f. Wastewater lagoon .........................................................................................................t321 1 Yes 3 No

g. Other (specify: _________________________) t322oth ......................................................t322 1 Yes 3 No

12. For those water bodies within 350 yards, approximately how many

of the following types of waterfowl were seen on the water during

the 14-day defined risk period?

a. Ducks........................................ t323 1 None 2 Tens 3 Hundreds 4 Thousands 5 Don’t know

b. Geese........................................ t324 1 None 2 Tens 3 Hundreds 4 Thousands 5 Don’t know

c. Shorebirds

(e.g., wading birds, gulls).......... t325 1 None 2 Tens 3 Hundreds 4 Thousands 5 Don’t know

d. Other 

(specify: ________)t326oth .................. t326 1 None 2 Tens 3 Hundreds 4 Thousands 5 Don’t know

13. What is the approximate distance (in yards) to the closest field 

where crops or hay are harvested?........................................................................................ t327 _____ yards

14. What crop was last grown in this field? [Check one only.] t328

1 Corn

2 Soybeans

3 Alfalfa or grass intended for livestock feed

4 Other (specify: _______________________________) t328oth

15. Was this field tilled last fall?................................................................ t329 1 Yes 3 No 4 Don’t know
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS 47

16. Was this field actively worked (e.g., tilled, disked, 

hay harvested, trees cut, row crops harvested) during 

the 14-day defined risk period? ................................................................. t330 1 Yes 3 No 4 Don’t know

17. For this closest field, approximately how many of the following

types of waterfowl were seen during the 14-day defined risk period?

a. Ducks........................................ t331 1 None 2 Tens 3 Hundreds 4 Thousands 5 Don’t know

b. Geese........................................ t332 1 None 2 Tens 3 Hundreds 4 Thousands 5 Don’t know

c. Shorebirds

(e.g., wading birds, gulls).......... t333 1 None 2 Tens 3 Hundreds 4 Thousands 5 Don’t know

d. Other 

(specify: ________) t334oth .......... t334 1 None 2 Tens 3 Hundreds 4 Thousands 5 Don’t know

18. What other types of animals are present on the farm premises?

a. Beef cattle ........................................................................................................................t335 1 Yes 3 No

b. Dairy cattle .......................................................................................................................t336 1 Yes 3 No

c. Horses...............................................................................................................................t337 1 Yes 3 No

d. Sheep................................................................................................................................t338 1 Yes 3 No

e. Goats ................................................................................................................................t339 1 Yes 3 No

f. Pigs ..................................................................................................................................t340 1 Yes 3 No

g. Dogs .................................................................................................................................t341 1 Yes 3 No

h. Cats ..................................................................................................................................t342 1 Yes 3 No

i. Poultry or domesticated waterfowl (noncommercial) ....................................................t343 1 Yes 3 No

j. Other (specify: _____________________) t344oth..............................................................t344 1 Yes 3 No

19. What is the water source for poultry?

a. Municipal...................................................................................................................t345 1 Yes 3 No

b. Well ...........................................................................................................................t346 1 Yes 3 No

c. Surface water (e.g., pond).........................................................................................t347 1 Yes 3 No

d. Other (specify: __________________________) t348oth.............................................t348 1 Yes 3 No

20. Are the following water treatments used in the drinking water 

for the poultry on this farm?

a. Chlorination......................................................................................................................t349 1 Yes 3 No

b. Acidifiers...........................................................................................................................t350 1 Yes 3 No

c. Iodine................................................................................................................................t351 1 Yes 3 No

d. Peroxide ...........................................................................................................................t352 1 Yes 3 No

e. Other (specify: ________________________________) t353oth ........................................t353 1 Yes 3 No
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

48 USDA APHIS VS

21. Are windbreaks present on this farm?

If Yes, what is the distance (in yards) from the windbreak to the closest poultry barn?

Windbreak type Present?

If Yes, distance to 

closest poultry barn

a. Evergreen or juniper 1 Yes 3 No _______ yards t354/t357

b. Deciduous tree 1 Yes 3 No _______ yards t355/t358

c. Structural (e.g., hill, natural break) 1 Yes 3 No _______ yards t356/t359

22. Excluding driveways on farm, what is the distance (in yards or miles) 

from this farm to the nearest public gravel or dirt road? ..................t360y/t360m _____yards OR _____ miles

23. What is the direction from this public roadway to the farm?......................................................... t361 _______ direction

C. FARM BIOSECURITY

1. Is there a house with people living in it on the property? ......................................................t401 1 Yes 3 No 

[If question 1 = No, SKIP to question 3.]

2. Is there a common drive entrance to farm and residence? ....................................................t402 1 Yes 3 No

3. How many entrances are there to the farm that could provide 

access to the poultry area? .....................................................................................................t403 _____ #

4. What best describes the road surface on this farm that vehicles coming 

onto the operation drive on? [Check one only.] t404

1 Hard top/asphalt

2 Gravel

3 Dirt

4 Other (specify: ________________________________________) t404oth
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS 49

5. In general, do the following types of vehicles:

Codes for question 5

1 = come to the perimeter of the farm only

2 = enter the farm but not near the barns

3 = come near the barns

4 = do not come at all 

Enter the codes that apply.

a. Garbage/dumpster pick up?.............................................................................................t405 _____ code

b. Propane delivery?.............................................................................................................t406 _____ code

c. Feed delivery? ..................................................................................................................t407 _____ code

d. Renderer?.........................................................................................................................t408 _____ code

e. Company personnel (e.g., catch/vaccination crew, barn workers,

service person, veterinarian)?..........................................................................................t409 _____ code

f. Other business visitors (e.g., meter reader, repairman)? ................................................t411 _____ code

6. Is there a gate to this farm entrance? .....................................................................................t412 1 Yes 3 No 

[If question 6 = No, SKIP to question 8.]

7. Is the gate secured/locked? ....................................................................................................t413 1 Yes 3 No

8. Is the farm area perimeter surrounded by a security fence?..................................................t414 1 Yes 3 No

9. How frequently is vegetation mowed/bush hogged on the premises 

(answer for when vegetation is present, e.g., spring and summer).................................t415 _____ times/month

10. Was there a wash station/spray area being used for vehicles 

during the 14-day defined risk period? ...................................................................................t416 1 Yes 3 No 

[If question 10 = No, SKIP to question 12.]
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

50 USDA APHIS VS

11. For wash station/spray area:

a. Is it located on the farm? .................................................................................................t417 1 Yes 3 No

b. Are the tires washed?.......................................................................................................t418 1 Yes 3 No

c. Is the vehicle exterior washed?........................................................................................t419 1 Yes 3 No

d. Is the vehicle interior cleaned (e.g., floor mats)...............................................................t420 1 Yes 3 No

e. Which vehicles are washed:

i. Worker vehicles?.......................................................................................................t421 1 Yes 3 No

ii. Feed trucks? ..............................................................................................................t422 1 Yes 3 No

iii. Vehicles delivering/removing birds?.........................................................................t423 1 Yes 3 No

iv. Other? (specify: ___________________________) t424oth .........................................t424 1 Yes 3 No

f. What disinfectant is used? _______________________________ t425

g. Was the wash station: [Check one only.] t426

1 Recently put into use as a response to heightened biosecurity concerns?

2 A permanent station (i.e., in use prior to the HPAI incident)?

12. Did workers and visitors always, sometimes, or never park in 

a restricted area away from the poultry barns during the 

14-day defined risk period?

a. Workers................................................................................. t427 1 Always 2 Sometimes 3 Never

b. Visitors................................................................................... t428 1 Always 2 Sometimes 3 Never

13. What pest and wildlife control measures were used on this farm 

during the 14-day defined risk period?

a. Rat and mouse bait stations?...........................................................................................t429 1 Yes 3 No

If Yes, how frequently are they checked? .................................................................t430 _____ times/month

b. Beetle control? .................................................................................................................t431 1 Yes 3 No

If Yes, what type was used?

i. Sprays.................................................................................................................t432 1 Yes 3 No

ii. Boric acid............................................................................................................t433 1 Yes 3 No

iii. Baits....................................................................................................................t434 1 Yes 3 No

iv. Other (specify: _____________________________) t435oth................................t435 1 Yes 3 No
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS 51

c. Fly control (other than manure removal)? ..................................................................... b436 1 Yes 3 No

If Yes, what type was used?

i. Residual spray ....................................................................................................t437 1 Yes 3 No

ii. Baits....................................................................................................................t438 1 Yes 3 No

iii. Larvacide (spot treatment) ................................................................................t439 1 Yes 3 No

iv. Larvacide in feed ................................................................................................t440 1 Yes 3 No

v. Space sprays/fogger...........................................................................................t441 1 Yes 3 No

vi. Biological predators ...........................................................................................t442 1 Yes 3 No

vii. Other (specify: ____________________________) t443oth..................................t443 1 Yes 3 No

14. How often were rodents observed in the poultry barns during 

the 14-day defined risk period? 

[Check one only.] t444

1 Frequently (e.g., daily)

2 Occasionally (e.g., weekly)

3 Never

15. What was the intensity of beetles observed in the poultry barns 

during the 14-day defined risk period? t445

[Check one only.]

1 High

2 Medium

3 Low

4 Never

16. What was the intensity of flies observed in the poultry barns during 

the 14-day defined risk period? t446

[Check one only.]

1 High

2 Medium

3 Low

17. Were wild mammals, such as raccoons, opossums, coyotes, or foxes 

(or evidence of their presence), seen in or around poultry barns 

during the 14-day defined risk period? ...................................................................................t447 1 Yes 3 No
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

52 USDA APHIS VS

18. During the 14-day defined risk period, prior to feeding, how frequently did wild birds, 

wild animals, and rodents have access to poultry feed (i.e., feed spillage, open bag, 

cover left open)?

Always/

nearly always

Most of 

the time Sometimes Never

a. Wild birds 1 2 3 4 t448

b. Wild animals such as 

raccoons, opossums, 

coyotes, or foxes

1 2 3 4 t449

c. Rodents 1 2 3 4 t450

19. Describe the protocol or plan for when feed spills on your farm: t451

_______________________________________________________________________________

20. What form of feed is fed to the poultry?

a. Mash...............................................................................................................................t452 1 Yes 3 No

b. Pellets.............................................................................................................................t453 1 Yes 3 No

c. Other (specify: __________________________________) t454oth...................................t454 1 Yes 3 No

21. Is the feed treated with formaldehyde (i.e., Termin-8)?...................................................t455 1 Yes 3 No

22. Is the feed heat treated? ...................................................................................................t456 1 Yes 3 No

D. WILD BIRDS

1. How frequently were the following types of wild birds seen on the farm, but outside 

of the barns (within 100 yards), during the 14-day defined risk period?

Bird type Often Sometimes Never

a. Waterfowl (e.g., ducks, geese) 1 2 3 t501

b. Gulls 1 2 3 t502

c. Small perching birds 

(e.g., sparrows, starlings, swallows) 1 2 3 t503

d. Blackbirds and crows 1 2 3 t504

e. Other water birds (e.g., egrets, cormorants) 1 2 3 t505

f. Wild turkeys, pheasants, quail 1 2 3 t506

g. Raptors (e.g., eagles, hawks, owls) 1 2 3 t507

h. Pigeons and doves 1 2 3 t508

i. Other (specify: ___________________) t509oth 1 2 3 t509
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS 53

2. How frequently were the following types of wild birds seen in the barns 

during the 14-day defined risk period?

Bird type Often Sometimes Never

a. Large birds (e.g., pigeons, crows) 1 2 3 t510

b. Small birds (e.g., finches, sparrows, starlings) 1 2 3 t511

c. Other (specify: ____________________) t512oth 1 2 3 t512

3. Did you observe any of the following types of dead wild birds in 

the barns or outside of the barns during the 14-day defined risk period?

Dead bird type Inside the barns? Outside the barns?

a. Large birds (e.g., pigeons, crows) 1 Yes 3 No 1 Yes 3 No t513/t516

b. Small birds (e.g., finches, sparrows, starlings) 1 Yes 3 No 1 Yes 3 No t514/t517

c. Other (specify: ____________________) t515oth 1 Yes 3 No 1 Yes 3 No t515/t518

E. FARM HELP/WORKERS

Questions in this section refer to persons such as the producer, employees, farm help, crews, etc.

1. What is the total number of employees working on this farm that have access to

or directly work with poultry (including family, both paid and unpaid)?....................................... t601 _____ #

2. During the 14-day defined risk period, were the following measures always/nearly always, most of the time, 

sometimes, or never required for workers entering the poultry barns?

Measure

Always/

nearly 

always

Most of the 

time Sometimes Never

a. An established clean/dirty line 1 2 3 4 t602

b. Shower 1 2 3 4 t603

c. Wash hands or use hand sanitizer before 

entering and/or before leaving the barn 1 2 3 4 t604

d. Different personnel for different barns 1 2 3 4 t605

e. Wear disposable coveralls 1 2 3 4 t606

f. Change of clothing (washable) 1 2 3 4 t607

g. Change of shoes or use of shoe covers 1 2 3 4 t608

h. Foot bath (liquid) 1 2 3 4 t609

i. Foot bath (dry) 1 2 3 4 t610

j. Scrub footwear (bucket and brush) 1 2 3 4 t611
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

54 USDA APHIS VS

3. Do workers on this farm work on other company farms? ......................................................t612 1 Yes 3 No

4. Are workers or members of their household employed by other 

poultry operations, rendering plants, or processing plants? ..................................................t613 1 Yes 3 No

5. Do any employees own their own poultry, 

including small backyard flocks? ................................................................ t614 1 Yes 3 No 4 Don’t know

6. Are employees required to stay off farm after exposure to other poultry? ...........................t615 1 Yes 3 No

If Yes, for how long (hours)?....................................................................................................t616 _____ hours

F. FARM VISITORS

1. Is a visitor log used to record visitor traffic onto the farm?....................................................t701 1 Yes 3 No

2. Did any of the following types of people visit the farm during the 14-day defined risk period?

If Yes, how many times did they visit and did they enter the poultry barn?

Visitor type

Did they visit 

the farm?

If Yes...

How many 

times did they 

visit?

Did this visitor 

enter the poultry 

barn?

a. Federal/State veterinary or 

animal health worker 1 Yes 3 No _____ # visits 1 Yes 3 No t702/t721/t740

b. Extension agent or university 

veterinarian 1 Yes 3 No _____ # visits 1 Yes 3 No t703/t722/t741

c. Private or company veterinarian 1 Yes 3 No _____ # visits 1 Yes 3 No t704/t723/t742

d. Company service person 1 Yes 3 No _____ # visits 1 Yes 3 No t705/t724/t743

e. Nutritionist or feed company 

consultant 1 Yes 3 No _____ # visits 1 Yes 3 No t706/t725/t744

f. Bird delivery personnel 1 Yes 3 No _____ # visits 1 Yes 3 No t707/t726/t745

g. Vaccination crew 1 Yes 3 No _____ # visits 1 Yes 3 No t708/t727/t746

h. Catch crew (bird removal) 1 Yes 3 No _____ # visits 1 Yes 3 No t709/t728/t747

i. Feed delivery personnel 1 Yes 3 No _____ # visits 1 Yes 3 No t710/t729/t748

j. Egg truck personnel (for breeder 

farms) 1 Yes 3 No _____ # visits 1 Yes 3 No t711/t730/t749

k. Litter delivery services 1 Yes 3 No _____ # visits 1 Yes 3 No t712/t731/t750

l. Litter removal services (e.g., litter 

broker, litter disposal) 1 Yes 3 No _____ # visits 1 Yes 3 No t713/t732/t751

m. Customer (private individual) 1 Yes 3 No _____ # visits 1 Yes 3 No t714/t733/t752

n. Wholesaler, buyer, or dealer 1 Yes 3 No _____ # visits 1 Yes 3 No t715/t734/t753

o. Renderer 1 Yes 3 No _____ # visits 1 Yes 3 No t716/t735/t754
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS 55

p. Occasional worker (e.g., family 

member, part-time help over 

holiday)

1 Yes 3 No _____ # visits 1 Yes 3 No t717/t736/t755

q. Construction workers, repair or 

maintenance personnel 1 Yes 3 No _____ # visits 1 Yes 3 No t718/t737/t756

r. Other business visitors (including 

other producers, meter readers, 

package delivery (UPS), etc.) 

1 Yes 3 No _____ # visits 1 Yes 3 No t719/t738/t757

s. Other nonbusiness visitors 

(including neighbors, family 

members, friends, and school 

field trips)

1 Yes 3 No _____ # visits 1 Yes 3 No t720/t739/t758

3. For those visitors who entered the poultry barn during the 14-day defined risk period, did you 

require the following?

Yes, verified 

at farm

Yes, visitor 

responsibility No

a. Change of outer clothing/

farm specific clothing 1 2 3 t759

b. Foot covers or change of footwear 1 2 3 t760

c. Mask 1 2 3 t761

d. Hand sanitizing or gloves 1 2 3 t762

e. Not visit multiple farms in the same day 1 2 3 t763

f. Other (specify:_______________) t764oth 1 2 3 t764

G. FARM VEHICLES AND EQUIPMENT

1. Were the following vehicles shared with another farm during the 14-day defined risk period?

Vehicle type Shared with another farm?

a. Company trucks/trailers (e.g., pickup truck, trailer with supplies, 

supervisor truck, etc.) 1 Yes 3 No t801

b. Feed trucks 1 Yes 3 No t802

c. Bird delivery vehicles (i.e., placing birds) 1 Yes 3 No t803

d. Bird removal vehicles 1 Yes 3 No t804

e. Egg removal vehicles (for breeder farms) 1 Yes 3 No t805

f. Manure/litter hauling 1 Yes 3 No t806

g. ATV/4-wheeler 1 Yes 3 No t807

h. Other (specify: ____________________________) t808oth 1 Yes 3 No t808

2. Were the following pieces of equipment shared with another farm during the 14-day defined risk period?
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

56 USDA APHIS VS

Equipment type Shared with another farm?

a. Gates/panels 1 Yes 3 No t810

b. Lawn mowers 1 Yes 3 No t811

c. Live haul loaders 1 Yes 3 No t812

d. Catch pens 1 Yes 3 No t813

e. Scales for weighing birds 1 Yes 3 No t814

f. Vaccination equipment 1 Yes 3 No t815

g. Pressure sprayers/washers/foamers 1 Yes 3 No t816

h. Skid-steer loaders 1 Yes 3 No t817

i. Litter/manure handling 1 Yes 3 No t818

j. Tillers/de-caking equipment 1 Yes 3 No t819

j. Other (specify: ________________________) t820oth 1 Yes 3 No t820

H. LITTER HANDLING

1. What was the last day litter was brought onto the farm? ........................................t901 _______ mm/dd/yy

2. For the last litter (bedding) delivery, who brought the litter onto the farm?

[Check one only.] t902

1 Company personnel

2 Litter provider

3 Other? (specify: __________________________________) t902oth

3. Is the litter heat treated prior to delivery? .................................. t903 1 Yes 3 No 4 Don’t know

4. Is litter stored on the farm prior to use:

a. Outside? ...........................................................................................................................t904 1 Yes 3 No

If Yes, is it covered? .........................................................................................................t905 1 Yes 3 No

b. In a shed? .........................................................................................................................t906 1 Yes 3 No

If Yes, is the shed closed?.................................................................................................t907 1 Yes 3 No

[If both questions 4a and 4b = No, SKIP to question 7.]

5. What is the minimum distance (in yards) from the on-site 

litter storage area to the nearest barn?.................................................................... t908 _____ yards
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS 57

6. Prior to use, is litter accessible to:

a. Wild birds? .......................................................................................................................t909 1 Yes 3 No

b. Wild animals (e.g., raccoons, opossum, coyotes, foxes)? ................................................t910 1 Yes 3 No

c. Domestic animals (e.g., dogs, cats)? ...............................................................................t911 1 Yes 3 No

7. What was the date that litter was last removed from any 

barn on this farms?....................................................................................................... t912 ________ mm/dd/yy

8. How was litter disposed of most recently?

a. Composted on-farm .........................................................................................................t913 1 Yes 3 No

If Yes, what is the distance (in yards) to the nearest poultry barn?.................................t914 ____ yards

b. Stored on-farm.................................................................................................................t916 1 Yes 3 No

c. Applied to land on this farm.............................................................................................t917 1 Yes 3 No

If Yes, what was the date litter was applied to land?................................................t918 ________ mm/dd/yy

d. Taken off-site....................................................................................................................t919 1 Yes 3 No

9. Has manure or used litter from other farms been 

spread on this farm or adjacent farms? ..................................................... t920 1 Yes 3 No 4 Don’t know

I. DEAD BIRD DISPOSAL

1. What is the approximate normal daily mortality on this farm? .............................. t1001 _____ #/day

Note: Ratio this number to number of birds in section A, question 2c or 3c (p 4).

Verify if the mortality is more than 0.01 (1 percent).

2. What are the method(s) of dead bird (daily mortality) disposal on this farm?

a. Composting .....................................................................................................................t1002 1 Yes 3 No

b. Burial ..............................................................................................................................t1003 1 Yes 3 No

c. Incineration .....................................................................................................................t1004 1 Yes 3 No

d. Rendering ........................................................................................................................t1005 1 Yes 3 No

e. Landfill.............................................................................................................................t1006 1 Yes 3 No

f. Other (specify: _______________________________) t1007oth ........................................t1007 1 Yes 3 No

3. If question 2a (composting) or question 2b (burial) 

is Yes, how frequently are carcasses covered with:

a. Soil? ....................................................................... t1008 1 Daily 2 Every 2 or more days 3 Never

b. Manure? ................................................................ t1009 1 Daily 2 Every 2 or more days 3 Never
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

58 USDA APHIS VS

4. If question 2d (rendering) is Yes, 

a. Is the carcass bin kept covered? .....................................................................................t1010 1 Yes 3 No

b. Are carcasses: [Check one only.] t1011

1 Taken by the producer/worker to the renderer?

2 Picked up by the renderer from the farm?

c. How many times were carcasses moved to the renderer 

during the 14-day defined risk period? ............................................................ t1012 _______ # times

5. What do workers do after handling the carcass bin before returning to the live poultry area? t1013

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

6. Were any wild birds or wild mammals observed around the dead bird collection 

area (i.e., burial, compost pile, rendering bin, etc.) during the 14-day defined 

risk period? 

a. Wild birds ........................................................................................................................t1014 1 Yes 3 No

b. Wild mammals.................................................................................................................t1015 1 Yes 3 No

7. Is there a common collection point (i.e., located off the farm) 

for dead bird disposal? ...........................................................................................................t1016 1 Yes 3 No

If Yes, where is the common collection point located? ________________________________ t1017
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS 59

BARN-LEVEL QUESTIONS

INSTRUCTIONS: 

1. Control farm: Select one barn to complete this section. Answer questions for the 14 days prior to 

the reference date specified on page 4 (the defined risk period).

2. Case farm: Select the first barn on this premises that was confirmed to be HPAI positive. Answer 

questions for the 14 days prior to the onset of clinical signs or increased mortality (the defined risk 

period).

1. What is the barn ID? t1101

2. How many barns (flocks) are in the barn structure? _____ # barns

3. What separates this barn (flock) from another barn 

(flock)?

1 Separate barn structure

1 Fence

1 Solid wall

t1102

4. Are the following type(s) of poultry are present in this 

barn?

a. Brooder 1 Yes 3 No t1103

b. Grower toms 1 Yes 3 No t1104

c. Grower hens 1 Yes 3 No t1105

d. Breeders 1 Yes 3 No t1106

e. Other

1 Yes 3 No

If Yes, specify: ______________

t1107/t1107oth

5. Did birds in this barn have outside access? 1 Yes 3 No t1108

6. How many birds were placed in this barn? _____ # birds t1109

7. What was the date of placement in this barn? ______ mm/dd/yy t1110

8. How old were birds when placed in this barn? ______days OR _____weeks t1111d/t1111w

9. Were different stages of production (e.g., brooders 

and growers) present in this barn at the same time? 1 Yes 3 No t1112

10. Was there another health concern in this flock during 

the defined risk period?

1 Yes 3 No

If Yes, specify condition: 

______________

______________

t1113/t1113oth

11. Was this flock being treated for a condition or health 

concern during the defined risk period? 1 Yes 3 No t1114

12. How old is this barn structure? _____ years t1115

13. How long has it been since the last 

remodel of the barn structure? _____ years t1116
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

60 USDA APHIS VS

14. How well has the barn structure been maintained?

[Enter code 1, 2, or 3.]

1. Well

E.g., walls, curtains, and mud boards do not have 

holes, no visible daylight, the barn is tight and well 

insulated

2. Moderate

E.g., barn could have rust or small holes, mud 

boards may be damaged, curtains may be torn or 

not in good repair, curtains may not close all the 

way, insulation may not be in good repair, the 

poly may be hanging from the ceiling

3. Poor

E.g., holes in walls and mud boards are apparent, 

tin is rusted, may have leaks in roof, there might 

be some holes large enough for wild birds to enter, 

multiple areas with daylight visible, insulation may 

be hanging from the ceiling

_____ code t1117

15. What type of ventilation was used for this barn during 

the 14 day defined risk period? [Enter Code 1, 2, 3, or 

4.]

1. Curtain ventilated

2. Environmental control/tunnel ventilation

3. Side doors (i.e., tip outs)

4. Other 

_____ code

If 4 (Other), specify: 

____________________________

t1118/t1118oth

16. If controller information is available, enter the 

percentage of time that curtains were open and the 

numbers of days open or partially open during the 

defined risk period.

_____ % time

_____ # days

t1119pct/t1119d

17. Is intake air filtered? 

1 Yes 3 No

If Yes, specify type of filter: 

______________ t1120/t1120oth

18. What were the minimum and maximum temperatures 

in the barn during the 14-day defined risk period?

Minimum: __________

Maximum: __________

t1121/t1122

19. Have you had to repair or replace any feed tank lids in 

the past 14 days? 1 Yes 3 No t1123

20. Have you noticed any feed tank lids open in the past 14 

days? 1 Yes 3 No t1124
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS 61

21. Which best describes the ground surface immediately 

surrounding (within 1 yard) this barn (excluding vehicle 

approach and loading area). [Enter Code 1, 2, 3, or 4.]

1. Gravel or hard surface

2. Dirt

3. Short grass

4. Tall grass or brush

_____ code t1125

22. Does this barn have a hard-surface entry pad (e.g., 

concrete, asphalt)?

1 Yes 3 No t1126

If Yes,

a. Is the entry pad cleaned and how frequently?

1 Yes, 3 No

If Yes, specify frequency: 

_______________

t1127/t1127oth

b. Is disinfectant used? 1 Yes 3 No t1128

23. How frequently were the following used in this barn 

during the 14-day defined risk period?

a. Locks on the doors

1 Used regularly

2 Not used regularly

3 Not available

t1129

b. A service room that personnel must enter through 

that separates “outside area” from “inside area” 

1 Used regularly

2 Not used regularly

3 Not available

t1130

c. Changing area for employees

1 Used regularly

2 Not used regularly

3 Not available

t1131

d. A shower for employees

1 Used regularly

2 Not used regularly

3 Not available

t1132

e. Cool cell pads

1 Used regularly

2 Not used regularly

3 Not available

t1133

f. Misters

1 Used regularly

2 Not used regularly

3 Not available 

t1134

24. What type of footbath is in use at this barn? [Enter 

Code 1, 2, 3, or 4.]

1. Dry (i.e., powdered or particulate)

2. Liquid

3. Other

4. None

_____ code

If 3 (Other), specify: _______________

[If 4 (None), SKIP to question 27.]

t1135/t1135oth

25. What is the frequency that footbath 

solutions are changed?

_____ times/ 

1 day, 2 week, or 3 month

t1136/t1136f

26. What disinfectant is used in the footbaths? t1137
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

62 USDA APHIS VS

27. What type(s) of litter is used in this barn?

[Enter Code 1, 2, 3, or 4.]

1. Wood shavings

2. Hulls (e.g., oat, rice, sunflower, other)

3. Straw

4. Other

_____ code

If 4 (Other), specify: _______________

t1138/t1138oth

28. Is the litter bagged (i.e., bailed) or 

bulk (i.e., load from shavings mill)? 1 Bag 2 Bulk t1139

29. Who are the supplier(s)/source(s) of litter? t1140

30. Was litter “tilled” after it was placed in the barn? 1 Yes 3 No t1141

If Yes, when was it tilled? ______ mm/dd/yy t1142

31. How many times was litter added to the barn during 

the defined risk period? _______ times t1143

32. What was the date of the last partial clean out in this 

barn (during the 14-day defined risk period)?

______ mm/dd/yy

1 No partial cleanout

t11441/t1144n

If a partial cleanout was done, who performed the 

partial cleanout?

[Enter Code 1 or 2.]

1. Grower

2. Contractor

_____ code t1145

If contractor, specify name and location:

Name: ________________

Location: ________________

t1146n/t1146l

33. When was the last full clean out?

[Enter Code 1, 2, or 3.]

1. Prior to this flock

2. Two flocks ago

3. Three or more flocks ago

_____ code t1147

If a full cleanout was performed, who performed the 

full cleanout?

[Enter Code 1 or 2.]

1. Grower

2. Contractor

_____ code t1148

If contractor, specify name and location:

Name: ________________

Location: ________________

t1149n/t114

9l

34. Was there a partial load-out while this flock was 

present? 1 Yes 3 No t1150

If Yes, what was the date? _______ mm/dd/yy t1151
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

USDA APHIS VS 63

35. Were the following wild birds seen in this barn during 

the 14-day defined risk period? 

a. Large birds (e.g., pigeons, crows) 1 Yes 3 No t1152

b. Small birds (e.g., finches, sparrows, starlings) 1 Yes 3 No t1153

36. How far is this barn (in yards) from:

a. Dead bird disposal/holding area including carcass 

bin for rendering?

____ yards t1154

b. Litter compost?

____ yards

1 Litter not composted

t1155/t1155

n

c. Nearest road? ____ yards t1156

37. Did any of the following types of people enter this 

barn during the 14-day defined risk period?

a. Federal/State veterinary or animal health worker 1 Yes 3 No t1157

b. Extension agent or university veterinarian 1 Yes 3 No t1158

c. Private or company veterinarian 1 Yes 3 No t1159

d. Company service person 1 Yes 3 No t1160

e. Nutritionist or feed company consultant 1 Yes 3 No t1161

f. Bird delivery personnel 1 Yes 3 No t1162

g. Vaccination crew 1 Yes 3 No t1163

h. Catch crew (bird removal) 1 Yes 3 No t1164

i. Feed delivery personnel 1 Yes 3 No t1165

j. Egg truck personnel (for breeder farms) 1 Yes 3 No t1166

k. Litter delivery services 1 Yes 3 No t1167

l. Litter removal services (e.g., litter broker, litter 

disposal) 1 Yes 3 No t1168

m. Customer (private individual) 1 Yes 3 No t1169

n. Wholesaler, buyer, or dealer 1 Yes 3 No t1170

o. Renderer 1 Yes 3 No t1171

p. Occasional worker (e.g., family member, part time 

help over holiday) 1 Yes 3 No t1172

q. Construction workers, repair or maintenance 

person

1 Yes 3 No t1173

r. Other business visitors (including other producers, 

meter readers, package delivery (UPS), etc.) 1 Yes 3 No t1174

s. Other nonbusiness visitors (including neighbors, 

friends, family members, and school field trips) 1 Yes 3 No t1175
Epidemiologic and Other Analyses of Indiana HPAI/LPAI-Affected Poultry Flocks

64 USDA APHIS VS

CHECKLIST

INSTRUCTIONS

This section refers to data that can be acquired through other sources.

1. Please verify grayed areas from the questionnaire.

2. If possible, attach a diagram, farm map, or photographs showing orientation of barn(s),

including barn numbers, water location, feed storage, rendering bin, litter storage, 

ventilation, and windbreaks.

3. If possible, attach photographs of exterior of study barn(s) showing:

• Exterior structure of the study barn(s), and 

• Ventilation system including exhaust fans and air input and curtains (if present).

4. How many commercial poultry farms (of any production type) are located:

a. Within 1 mile of this farm? ......................................................................... t1201 _______ #

b. Within 3 miles of this farm? ....................................................................... t1202 _______ #

5. How far (in yards or miles) is the nearest 

backyard flock to this farm?............................................. t1203y/t1203m _____ yards OR _____ miles

6. How far (in yards or miles) is the nearest HPAI-positive premises 

to this farm? ..................................................................... t1204y/t1204m _____ yards OR _____ miles

7. Collect feed or live haul truck routing information, if available. Determine if 

trucks are routed to avoid passing positive premises.

8. Collect mortality sheets from both case and control barns.

9. Collect ventilation control information, if available.

10. If available, collect weather data, including historical baselines, relative humidity,

wind direction, temperature, and cloud cover.

11. Collect specific age and date of placement for each barn.

12. Which feed mill supplies feed to this farm? t1205

__________________________________________________________